{"id":58224,"date":"2025-08-16T06:59:46","date_gmt":"2025-08-15T22:59:46","guid":{"rendered":"https:\/\/www.wsisp.com\/helps\/58224.html"},"modified":"2025-08-16T06:59:46","modified_gmt":"2025-08-15T22:59:46","slug":"%e6%97%a0%e7%ba%bf%e9%80%9a%e4%bf%a1%e5%9f%ba%e7%a1%80%ef%bc%9a%e8%b0%83%e5%88%b6%e4%b8%8e%e8%a7%a3%e8%b0%83%e6%8a%80%e6%9c%af_%ef%bc%8844%ef%bc%89-7-4%e6%ad%a3%e4%ba%a4%e5%b9%85%e5%ba%a6%e8%a7%a3","status":"publish","type":"post","link":"https:\/\/www.wsisp.com\/helps\/58224.html","title":{"rendered":"\u65e0\u7ebf\u901a\u4fe1\u57fa\u7840\uff1a\u8c03\u5236\u4e0e\u89e3\u8c03\u6280\u672f_\uff0844\uff09.7.4\u6b63\u4ea4\u5e45\u5ea6\u89e3\u8c03(QAM\u89e3\u8c03)"},"content":{"rendered":"<h4>7.4 \u6b63\u4ea4\u5e45\u5ea6\u89e3\u8c03 (QAM\u89e3\u8c03)<\/h4>\n<p>\u5728\u65e0\u7ebf\u901a\u4fe1\u7cfb\u7edf\u4e2d&#xff0c;\u6b63\u4ea4\u5e45\u5ea6\u8c03\u5236&#xff08;Quadrature Amplitude Modulation, QAM&#xff09;\u662f\u4e00\u79cd\u5e38\u7528\u7684\u591a\u8fdb\u5236\u8c03\u5236\u6280\u672f&#xff0c;\u5b83\u901a\u8fc7\u540c\u65f6\u6539\u53d8\u8f7d\u6ce2\u7684\u632f\u5e45\u548c\u76f8\u4f4d\u6765\u4f20\u8f93\u4fe1\u606f\u3002QAM\u89e3\u8c03\u5219\u662f\u5c06\u63a5\u6536\u5230\u7684QAM\u4fe1\u53f7\u6062\u590d\u6210\u539f\u59cb\u7684\u6570\u5b57\u4fe1\u606f\u7684\u8fc7\u7a0b\u3002\u672c\u8282\u5c06\u8be6\u7ec6\u63a2\u8ba8QAM\u89e3\u8c03\u7684\u539f\u7406\u3001\u6b65\u9aa4\u4ee5\u53ca\u5177\u4f53\u5b9e\u73b0\u65b9\u6cd5&#xff0c;\u5e76\u901a\u8fc7\u5b9e\u4f8b\u8fdb\u884c\u8bf4\u660e\u3002<\/p>\n<h5>7.4.1 QAM\u89e3\u8c03\u7684\u57fa\u672c\u539f\u7406<\/h5>\n<p>QAM\u89e3\u8c03\u7684\u57fa\u672c\u539f\u7406\u662f\u901a\u8fc7\u68c0\u6d4b\u63a5\u6536\u5230\u7684\u4fe1\u53f7\u7684\u632f\u5e45\u548c\u76f8\u4f4d\u6765\u6062\u590d\u539f\u59cb\u7684\u6570\u5b57\u4fe1\u606f\u3002QAM\u4fe1\u53f7\u53ef\u4ee5\u770b\u4f5c\u662f\u4e24\u4e2a\u6b63\u4ea4\u7684\u8f7d\u6ce2\u4fe1\u53f7\u7684\u53e0\u52a0&#xff0c;\u6bcf\u4e2a\u8f7d\u6ce2\u4fe1\u53f7\u5206\u522b\u643a\u5e26\u4e86\u4e0d\u540c\u7684\u4fe1\u606f\u3002\u5177\u4f53\u6765\u8bf4&#xff0c;QAM\u4fe1\u53f7\u53ef\u4ee5\u8868\u793a\u4e3a&#xff1a;<\/p>\n<p><span class=\"katex--display\"><span class=\"katex-display\"><span class=\"katex\"><span class=\"katex-mathml\">s(t)&#061;I(t)cos\u2061(2\u03c0fct)&#043;Q(t)sin\u2061(2\u03c0fct) s(t) &#061; I(t) \\\\cos(2\\\\pi f_c t) &#043; Q(t) \\\\sin(2\\\\pi f_c t) <\/span><span class=\"katex-html\"><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord mathnormal\">s<\/span><span class=\"mopen\">(<\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><span class=\"mspace\" style=\"margin-right: 0.2778em\"><\/span><span class=\"mrel\">&#061;<\/span><span class=\"mspace\" style=\"margin-right: 0.2778em\"><\/span><\/span><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord mathnormal\" style=\"margin-right: 0.0785em\">I<\/span><span class=\"mopen\">(<\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><span class=\"mspace\" style=\"margin-right: 0.1667em\"><\/span><span class=\"mop\">cos<\/span><span class=\"mopen\">(<\/span><span class=\"mord\">2<\/span><span class=\"mord mathnormal\" style=\"margin-right: 0.0359em\">\u03c0<\/span><span class=\"mord\"><span class=\"mord mathnormal\" style=\"margin-right: 0.1076em\">f<\/span><span class=\"msupsub\"><span class=\"vlist-t vlist-t2\"><span class=\"vlist-r\"><span class=\"vlist\" style=\"height: 0.1514em\"><span class=\"\" style=\"top: -2.55em;margin-left: -0.1076em;margin-right: 0.05em\"><span class=\"pstrut\" style=\"height: 2.7em\"><\/span><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mathnormal mtight\">c<\/span><\/span><\/span><\/span><span class=\"vlist-s\">\u200b<\/span><\/span><span class=\"vlist-r\"><span class=\"vlist\" style=\"height: 0.15em\"><span class=\"\"><\/span><\/span><\/span><\/span><\/span><\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><span class=\"mspace\" style=\"margin-right: 0.2222em\"><\/span><span class=\"mbin\">&#043;<\/span><span class=\"mspace\" style=\"margin-right: 0.2222em\"><\/span><\/span><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord mathnormal\">Q<\/span><span class=\"mopen\">(<\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><span class=\"mspace\" style=\"margin-right: 0.1667em\"><\/span><span class=\"mop\">sin<\/span><span class=\"mopen\">(<\/span><span class=\"mord\">2<\/span><span class=\"mord mathnormal\" style=\"margin-right: 0.0359em\">\u03c0<\/span><span class=\"mord\"><span class=\"mord mathnormal\" style=\"margin-right: 0.1076em\">f<\/span><span class=\"msupsub\"><span class=\"vlist-t vlist-t2\"><span class=\"vlist-r\"><span class=\"vlist\" style=\"height: 0.1514em\"><span class=\"\" style=\"top: -2.55em;margin-left: -0.1076em;margin-right: 0.05em\"><span class=\"pstrut\" style=\"height: 2.7em\"><\/span><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mathnormal mtight\">c<\/span><\/span><\/span><\/span><span class=\"vlist-s\">\u200b<\/span><\/span><span class=\"vlist-r\"><span class=\"vlist\" style=\"height: 0.15em\"><span class=\"\"><\/span><\/span><\/span><\/span><\/span><\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><\/span><\/span><\/span><\/span><\/span><\/p>\n<p>\u5176\u4e2d&#xff0c;<span class=\"katex--inline\"><span class=\"katex\"><span class=\"katex-mathml\">I(t)I(t)<\/span><span class=\"katex-html\"><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord mathnormal\" style=\"margin-right: 0.0785em\">I<\/span><span class=\"mopen\">(<\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><\/span><\/span><\/span><\/span> \u548c <span class=\"katex--inline\"><span class=\"katex\"><span class=\"katex-mathml\">Q(t)Q(t)<\/span><span class=\"katex-html\"><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord mathnormal\">Q<\/span><span class=\"mopen\">(<\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><\/span><\/span><\/span><\/span> \u5206\u522b\u662f\u540c\u76f8\u5206\u91cf\u548c\u6b63\u4ea4\u5206\u91cf&#xff0c;<span class=\"katex--inline\"><span class=\"katex\"><span class=\"katex-mathml\">fcf_c<\/span><span class=\"katex-html\"><span class=\"base\"><span class=\"strut\" style=\"height: 0.8889em;vertical-align: -0.1944em\"><\/span><span class=\"mord\"><span class=\"mord mathnormal\" style=\"margin-right: 0.1076em\">f<\/span><span class=\"msupsub\"><span class=\"vlist-t vlist-t2\"><span class=\"vlist-r\"><span class=\"vlist\" style=\"height: 0.1514em\"><span class=\"\" style=\"top: -2.55em;margin-left: -0.1076em;margin-right: 0.05em\"><span class=\"pstrut\" style=\"height: 2.7em\"><\/span><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mathnormal mtight\">c<\/span><\/span><\/span><\/span><span class=\"vlist-s\">\u200b<\/span><\/span><span class=\"vlist-r\"><span class=\"vlist\" style=\"height: 0.15em\"><span class=\"\"><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span> \u662f\u8f7d\u6ce2\u9891\u7387\u3002\u89e3\u8c03\u7684\u76ee\u6807\u662f\u901a\u8fc7\u5bf9\u63a5\u6536\u5230\u7684\u4fe1\u53f7 <span class=\"katex--inline\"><span class=\"katex\"><span class=\"katex-mathml\">r(t)r(t)<\/span><span class=\"katex-html\"><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord mathnormal\" style=\"margin-right: 0.0278em\">r<\/span><span class=\"mopen\">(<\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><\/span><\/span><\/span><\/span> \u8fdb\u884c\u5904\u7406&#xff0c;\u6062\u590d\u51fa <span class=\"katex--inline\"><span class=\"katex\"><span class=\"katex-mathml\">I(t)I(t)<\/span><span class=\"katex-html\"><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord mathnormal\" style=\"margin-right: 0.0785em\">I<\/span><span class=\"mopen\">(<\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><\/span><\/span><\/span><\/span> \u548c <span class=\"katex--inline\"><span class=\"katex\"><span class=\"katex-mathml\">Q(t)Q(t)<\/span><span class=\"katex-html\"><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord mathnormal\">Q<\/span><span class=\"mopen\">(<\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><\/span><\/span><\/span><\/span>\u3002<\/p>\n<p>QAM\u89e3\u8c03\u901a\u5e38\u5305\u62ec\u4ee5\u4e0b\u51e0\u4e2a\u6b65\u9aa4&#xff1a;<\/p>\n<li>\u4e0b\u53d8\u9891&#xff1a;\u5c06\u63a5\u6536\u5230\u7684\u9ad8\u9891\u4fe1\u53f7\u8f6c\u6362\u4e3a\u4f4e\u9891\u4fe1\u53f7\u3002<\/li>\n<li>\u4f4e\u901a\u6ee4\u6ce2&#xff1a;\u6ee4\u9664\u9ad8\u9891\u566a\u58f0&#xff0c;\u4fdd\u7559\u6709\u7528\u4fe1\u53f7\u3002<\/li>\n<li>\u91c7\u6837&#xff1a;\u5728\u5408\u9002\u7684\u65f6\u95f4\u70b9\u5bf9\u4fe1\u53f7\u8fdb\u884c\u91c7\u6837&#xff0c;\u5f97\u5230\u79bb\u6563\u7684I\u548cQ\u5206\u91cf\u3002<\/li>\n<li>\u7b26\u53f7\u68c0\u6d4b&#xff1a;\u6839\u636e\u91c7\u6837\u503c\u5224\u65ad\u539f\u59cb\u7684\u6570\u5b57\u4fe1\u606f\u3002<\/li>\n<h5>7.4.2 \u4e0b\u53d8\u9891<\/h5>\n<p>\u4e0b\u53d8\u9891\u662fQAM\u89e3\u8c03\u7684\u7b2c\u4e00\u6b65&#xff0c;\u5176\u76ee\u7684\u662f\u5c06\u63a5\u6536\u5230\u7684\u9ad8\u9891\u4fe1\u53f7 <span class=\"katex--inline\"><span class=\"katex\"><span class=\"katex-mathml\">r(t)r(t)<\/span><span class=\"katex-html\"><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord mathnormal\" style=\"margin-right: 0.0278em\">r<\/span><span class=\"mopen\">(<\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><\/span><\/span><\/span><\/span> \u8f6c\u6362\u4e3a\u4f4e\u9891\u4fe1\u53f7\u3002\u8fd9\u53ef\u4ee5\u901a\u8fc7\u4e58\u4ee5\u672c\u5730\u632f\u8361\u5668\u7684\u540c\u76f8\u548c\u6b63\u4ea4\u8f7d\u6ce2\u4fe1\u53f7\u6765\u5b9e\u73b0\u3002\u5047\u8bbe\u63a5\u6536\u5230\u7684\u4fe1\u53f7\u4e3a&#xff1a;<\/p>\n<p><span class=\"katex--display\"><span class=\"katex-display\"><span class=\"katex\"><span class=\"katex-mathml\">r(t)&#061;s(t)&#043;n(t) r(t) &#061; s(t) &#043; n(t) <\/span><span class=\"katex-html\"><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord mathnormal\" style=\"margin-right: 0.0278em\">r<\/span><span class=\"mopen\">(<\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><span class=\"mspace\" style=\"margin-right: 0.2778em\"><\/span><span class=\"mrel\">&#061;<\/span><span class=\"mspace\" style=\"margin-right: 0.2778em\"><\/span><\/span><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord mathnormal\">s<\/span><span class=\"mopen\">(<\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><span class=\"mspace\" style=\"margin-right: 0.2222em\"><\/span><span class=\"mbin\">&#043;<\/span><span class=\"mspace\" style=\"margin-right: 0.2222em\"><\/span><\/span><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord mathnormal\">n<\/span><span class=\"mopen\">(<\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><\/span><\/span><\/span><\/span><\/span><\/p>\n<p>\u5176\u4e2d&#xff0c;<span class=\"katex--inline\"><span class=\"katex\"><span class=\"katex-mathml\">n(t)n(t)<\/span><span class=\"katex-html\"><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord mathnormal\">n<\/span><span class=\"mopen\">(<\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><\/span><\/span><\/span><\/span> \u662f\u52a0\u6027\u9ad8\u65af\u767d\u566a\u58f0&#xff08;Additive Gaussian White Noise, AWGN&#xff09;\u3002\u4e0b\u53d8\u9891\u540e\u7684\u4fe1\u53f7\u53ef\u4ee5\u8868\u793a\u4e3a&#xff1a;<\/p>\n<p><span class=\"katex--display\"><span class=\"katex-display\"><span class=\"katex\"><span class=\"katex-mathml\">rI(t)&#061;r(t)cos\u2061(2\u03c0fct) r_I(t) &#061; r(t) \\\\cos(2\\\\pi f_c t) <\/span><span class=\"katex-html\"><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord\"><span class=\"mord mathnormal\" style=\"margin-right: 0.0278em\">r<\/span><span class=\"msupsub\"><span class=\"vlist-t vlist-t2\"><span class=\"vlist-r\"><span class=\"vlist\" style=\"height: 0.3283em\"><span class=\"\" style=\"top: -2.55em;margin-left: -0.0278em;margin-right: 0.05em\"><span class=\"pstrut\" style=\"height: 2.7em\"><\/span><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mathnormal mtight\" style=\"margin-right: 0.0785em\">I<\/span><\/span><\/span><\/span><span class=\"vlist-s\">\u200b<\/span><\/span><span class=\"vlist-r\"><span class=\"vlist\" style=\"height: 0.15em\"><span class=\"\"><\/span><\/span><\/span><\/span><\/span><\/span><span class=\"mopen\">(<\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><span class=\"mspace\" style=\"margin-right: 0.2778em\"><\/span><span class=\"mrel\">&#061;<\/span><span class=\"mspace\" style=\"margin-right: 0.2778em\"><\/span><\/span><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord mathnormal\" style=\"margin-right: 0.0278em\">r<\/span><span class=\"mopen\">(<\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><span class=\"mspace\" style=\"margin-right: 0.1667em\"><\/span><span class=\"mop\">cos<\/span><span class=\"mopen\">(<\/span><span class=\"mord\">2<\/span><span class=\"mord mathnormal\" style=\"margin-right: 0.0359em\">\u03c0<\/span><span class=\"mord\"><span class=\"mord mathnormal\" style=\"margin-right: 0.1076em\">f<\/span><span class=\"msupsub\"><span class=\"vlist-t vlist-t2\"><span class=\"vlist-r\"><span class=\"vlist\" style=\"height: 0.1514em\"><span class=\"\" style=\"top: -2.55em;margin-left: -0.1076em;margin-right: 0.05em\"><span class=\"pstrut\" style=\"height: 2.7em\"><\/span><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mathnormal mtight\">c<\/span><\/span><\/span><\/span><span class=\"vlist-s\">\u200b<\/span><\/span><span class=\"vlist-r\"><span class=\"vlist\" style=\"height: 0.15em\"><span class=\"\"><\/span><\/span><\/span><\/span><\/span><\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><\/span><\/span><\/span><\/span><\/span><br \/>\n<span class=\"katex--display\"><span class=\"katex-display\"><span class=\"katex\"><span class=\"katex-mathml\">rQ(t)&#061;r(t)sin\u2061(2\u03c0fct) r_Q(t) &#061; r(t) \\\\sin(2\\\\pi f_c t) <\/span><span class=\"katex-html\"><span class=\"base\"><span class=\"strut\" style=\"height: 1.0361em;vertical-align: -0.2861em\"><\/span><span class=\"mord\"><span class=\"mord mathnormal\" style=\"margin-right: 0.0278em\">r<\/span><span class=\"msupsub\"><span class=\"vlist-t vlist-t2\"><span class=\"vlist-r\"><span class=\"vlist\" style=\"height: 0.3283em\"><span class=\"\" style=\"top: -2.55em;margin-left: -0.0278em;margin-right: 0.05em\"><span class=\"pstrut\" style=\"height: 2.7em\"><\/span><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mathnormal mtight\">Q<\/span><\/span><\/span><\/span><span class=\"vlist-s\">\u200b<\/span><\/span><span class=\"vlist-r\"><span class=\"vlist\" style=\"height: 0.2861em\"><span class=\"\"><\/span><\/span><\/span><\/span><\/span><\/span><span class=\"mopen\">(<\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><span class=\"mspace\" style=\"margin-right: 0.2778em\"><\/span><span class=\"mrel\">&#061;<\/span><span class=\"mspace\" style=\"margin-right: 0.2778em\"><\/span><\/span><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord mathnormal\" style=\"margin-right: 0.0278em\">r<\/span><span class=\"mopen\">(<\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><span class=\"mspace\" style=\"margin-right: 0.1667em\"><\/span><span class=\"mop\">sin<\/span><span class=\"mopen\">(<\/span><span class=\"mord\">2<\/span><span class=\"mord mathnormal\" style=\"margin-right: 0.0359em\">\u03c0<\/span><span class=\"mord\"><span class=\"mord mathnormal\" style=\"margin-right: 0.1076em\">f<\/span><span class=\"msupsub\"><span class=\"vlist-t vlist-t2\"><span class=\"vlist-r\"><span class=\"vlist\" style=\"height: 0.1514em\"><span class=\"\" style=\"top: -2.55em;margin-left: -0.1076em;margin-right: 0.05em\"><span class=\"pstrut\" style=\"height: 2.7em\"><\/span><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mathnormal mtight\">c<\/span><\/span><\/span><\/span><span class=\"vlist-s\">\u200b<\/span><\/span><span class=\"vlist-r\"><span class=\"vlist\" style=\"height: 0.15em\"><span class=\"\"><\/span><\/span><\/span><\/span><\/span><\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><\/span><\/span><\/span><\/span><\/span><\/p>\n<p>\u901a\u8fc7\u8fd9\u4e24\u4e2a\u4e58\u6cd5\u64cd\u4f5c&#xff0c;\u53ef\u4ee5\u5c06\u9ad8\u9891\u4fe1\u53f7 <span class=\"katex--inline\"><span class=\"katex\"><span class=\"katex-mathml\">s(t)s(t)<\/span><span class=\"katex-html\"><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord mathnormal\">s<\/span><span class=\"mopen\">(<\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><\/span><\/span><\/span><\/span> \u4e0b\u53d8\u9891\u5230\u57fa\u5e26\u4fe1\u53f7 <span class=\"katex--inline\"><span class=\"katex\"><span class=\"katex-mathml\">I(t)I(t)<\/span><span class=\"katex-html\"><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord mathnormal\" style=\"margin-right: 0.0785em\">I<\/span><span class=\"mopen\">(<\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><\/span><\/span><\/span><\/span> \u548c <span class=\"katex--inline\"><span class=\"katex\"><span class=\"katex-mathml\">Q(t)Q(t)<\/span><span class=\"katex-html\"><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord mathnormal\">Q<\/span><span class=\"mopen\">(<\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><\/span><\/span><\/span><\/span>\u3002<\/p>\n<h5>7.4.3 \u4f4e\u901a\u6ee4\u6ce2<\/h5>\n<p>\u4f4e\u901a\u6ee4\u6ce2\u5668\u7528\u4e8e\u6ee4\u9664\u4e0b\u53d8\u9891\u540e\u7684\u9ad8\u9891\u566a\u58f0&#xff0c;\u4fdd\u7559\u57fa\u5e26\u4fe1\u53f7\u3002\u7406\u60f3\u60c5\u51b5\u4e0b&#xff0c;\u4f4e\u901a\u6ee4\u6ce2\u5668\u7684\u622a\u6b62\u9891\u7387\u5e94\u8bbe\u7f6e\u4e3a\u57fa\u5e26\u4fe1\u53f7\u7684\u5e26\u5bbd\u3002\u5e38\u7528\u7684\u4f4e\u901a\u6ee4\u6ce2\u5668\u7c7b\u578b\u5305\u62ec\u5df4\u7279\u6c83\u65af\u6ee4\u6ce2\u5668\u3001\u5207\u6bd4\u96ea\u592b\u6ee4\u6ce2\u5668\u548c\u9ad8\u65af\u6ee4\u6ce2\u5668\u7b49\u3002<\/p>\n<h5>7.4.4 \u91c7\u6837<\/h5>\n<p>\u91c7\u6837\u662f\u5728\u4e0b\u53d8\u9891\u548c\u4f4e\u901a\u6ee4\u6ce2\u540e&#xff0c;\u901a\u8fc7\u5bf9\u57fa\u5e26\u4fe1\u53f7 <span class=\"katex--inline\"><span class=\"katex\"><span class=\"katex-mathml\">I(t)I(t)<\/span><span class=\"katex-html\"><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord mathnormal\" style=\"margin-right: 0.0785em\">I<\/span><span class=\"mopen\">(<\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><\/span><\/span><\/span><\/span> \u548c <span class=\"katex--inline\"><span class=\"katex\"><span class=\"katex-mathml\">Q(t)Q(t)<\/span><span class=\"katex-html\"><span class=\"base\"><span class=\"strut\" style=\"height: 1em;vertical-align: -0.25em\"><\/span><span class=\"mord mathnormal\">Q<\/span><span class=\"mopen\">(<\/span><span class=\"mord mathnormal\">t<\/span><span class=\"mclose\">)<\/span><\/span><\/span><\/span><\/span> \u8fdb\u884c\u91c7\u6837&#xff0c;\u5f97\u5230\u79bb\u6563\u7684I\u548cQ\u5206\u91cf\u3002\u91c7\u6837\u9891\u7387\u901a\u5e38\u5e94\u5927\u4e8e\u6216\u7b49\u4e8e\u57fa\u5e26\u4fe1\u53f7\u7684\u5948\u594e\u65af\u7279\u9891\u7387\u3002\u5e38\u89c1\u7684\u91c7\u6837\u65b9\u6cd5\u5305\u62ec\u8fc7\u91c7\u6837\u548c\u6b20\u91c7\u6837\u3002<\/p>\n<h5>7.4.5 \u7b26\u53f7\u68c0\u6d4b<\/h5>\n<p>\u7b26\u53f7\u68c0\u6d4b\u662f\u6839\u636e\u91c7\u6837\u5f97\u5230\u7684I\u548cQ\u5206\u91cf&#xff0c;\u5224\u65ad\u539f\u59cb\u7684\u6570\u5b57\u4fe1\u606f\u3002\u8fd9\u901a\u5e38\u901a\u8fc7\u5c06\u91c7\u6837\u503c\u4e0e\u9884\u5b9a\u4e49\u7684\u661f\u5ea7\u56fe\u8fdb\u884c\u6bd4\u8f83\u6765\u5b9e\u73b0\u3002\u661f\u5ea7\u56fe\u662fQAM\u8c03\u5236\u5668\u548c\u89e3\u8c03\u5668\u4e4b\u95f4\u7684\u4e00\u79cd\u7ea6\u5b9a&#xff0c;\u8868\u793a\u4e86\u6bcf\u4e2a\u7b26\u53f7\u5bf9\u5e94\u7684I\u548cQ\u5206\u91cf\u7684\u7ec4\u5408\u3002<\/p>\n<h4>7.4.6 QAM\u89e3\u8c03\u7684\u5b9e\u73b0<\/h4>\n<h5>7.4.6.1 \u4eff\u771f\u73af\u5883\u8bbe\u7f6e<\/h5>\n<p>\u5728\u672c\u8282\u4e2d&#xff0c;\u6211\u4eec\u5c06\u4f7f\u7528Python\u548cNumPy\u5e93\u6765\u5b9e\u73b0QAM\u89e3\u8c03\u7684\u4eff\u771f\u3002\u9996\u5148&#xff0c;\u786e\u4fdd\u4f60\u5df2\u7ecf\u5b89\u88c5\u4e86Python\u548cNumPy\u5e93\u3002\u5982\u679c\u6ca1\u6709\u5b89\u88c5&#xff0c;\u53ef\u4ee5\u901a\u8fc7\u4ee5\u4e0b\u547d\u4ee4\u8fdb\u884c\u5b89\u88c5&#xff1a;<\/p>\n<p>pip <span class=\"token function\">install<\/span> numpy<\/p>\n<p>\u63a5\u4e0b\u6765&#xff0c;\u5bfc\u5165\u5fc5\u8981\u7684\u5e93&#xff1a;<\/p>\n<p><span class=\"token keyword\">import<\/span> numpy <span class=\"token keyword\">as<\/span> np<br \/>\n<span class=\"token keyword\">import<\/span> matplotlib<span class=\"token punctuation\">.<\/span>pyplot <span class=\"token keyword\">as<\/span> plt<br \/>\n<span class=\"token keyword\">from<\/span> scipy<span class=\"token punctuation\">.<\/span>signal <span class=\"token keyword\">import<\/span> butter<span class=\"token punctuation\">,<\/span> lfilter<\/p>\n<h5>7.4.6.2 \u751f\u6210QAM\u4fe1\u53f7<\/h5>\n<p>\u4e3a\u4e86\u8fdb\u884cQAM\u89e3\u8c03\u7684\u4eff\u771f&#xff0c;\u6211\u4eec\u9996\u5148\u9700\u8981\u751f\u6210\u4e00\u4e2aQAM\u4fe1\u53f7\u3002\u5047\u8bbe\u6211\u4eec\u4f7f\u752816-QAM\u8c03\u5236&#xff0c;\u751f\u6210\u7684\u4fe1\u53f7\u5982\u4e0b&#xff1a;<\/p>\n<p><span class=\"token comment\"># \u751f\u621016-QAM\u661f\u5ea7\u56fe<\/span><br \/>\n<span class=\"token keyword\">def<\/span> <span class=\"token function\">generate_16qam_constellation<\/span><span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">:<\/span><br \/>\n    symbols <span class=\"token operator\">&#061;<\/span> np<span class=\"token punctuation\">.<\/span>array<span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">[<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">3<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token operator\">&#8211;<\/span><span class=\"token number\">3<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token operator\">&#8211;<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">]<\/span><span class=\"token punctuation\">)<\/span><br \/>\n    constellation <span class=\"token operator\">&#061;<\/span> <span class=\"token punctuation\">[<\/span><span class=\"token punctuation\">]<\/span><br \/>\n    <span class=\"token keyword\">for<\/span> i <span class=\"token keyword\">in<\/span> symbols<span class=\"token punctuation\">:<\/span><br \/>\n        <span class=\"token keyword\">for<\/span> q <span class=\"token keyword\">in<\/span> symbols<span class=\"token punctuation\">:<\/span><br \/>\n            constellation<span class=\"token punctuation\">.<\/span>append<span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">(<\/span>i<span class=\"token punctuation\">,<\/span> q<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><br \/>\n    <span class=\"token keyword\">return<\/span> np<span class=\"token punctuation\">.<\/span>array<span class=\"token punctuation\">(<\/span>constellation<span class=\"token punctuation\">)<\/span><\/p>\n<p><span class=\"token comment\"># \u751f\u621016-QAM\u4fe1\u53f7<\/span><br \/>\n<span class=\"token keyword\">def<\/span> <span class=\"token function\">generate_16qam_signal<\/span><span class=\"token punctuation\">(<\/span>bits<span class=\"token punctuation\">,<\/span> constellation<span class=\"token punctuation\">,<\/span> carrier_freq<span class=\"token punctuation\">,<\/span> sample_rate<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">:<\/span><br \/>\n    symbols <span class=\"token operator\">&#061;<\/span> constellation<span class=\"token punctuation\">[<\/span>bits<span class=\"token punctuation\">]<\/span><br \/>\n    t <span class=\"token operator\">&#061;<\/span> np<span class=\"token punctuation\">.<\/span>arange<span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token builtin\">len<\/span><span class=\"token punctuation\">(<\/span>bits<span class=\"token punctuation\">)<\/span> <span class=\"token operator\">\/<\/span> sample_rate<span class=\"token punctuation\">,<\/span> <span class=\"token number\">1<\/span> <span class=\"token operator\">\/<\/span> sample_rate<span class=\"token punctuation\">)<\/span><br \/>\n    I <span class=\"token operator\">&#061;<\/span> symbols<span class=\"token punctuation\">[<\/span><span class=\"token punctuation\">:<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">]<\/span><br \/>\n    Q <span class=\"token operator\">&#061;<\/span> symbols<span class=\"token punctuation\">[<\/span><span class=\"token punctuation\">:<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1<\/span><span class=\"token punctuation\">]<\/span><br \/>\n    s_I <span class=\"token operator\">&#061;<\/span> I <span class=\"token operator\">*<\/span> np<span class=\"token punctuation\">.<\/span>cos<span class=\"token punctuation\">(<\/span><span class=\"token number\">2<\/span> <span class=\"token operator\">*<\/span> np<span class=\"token punctuation\">.<\/span>pi <span class=\"token operator\">*<\/span> carrier_freq <span class=\"token operator\">*<\/span> t<span class=\"token punctuation\">)<\/span><br \/>\n    s_Q <span class=\"token operator\">&#061;<\/span> Q <span class=\"token operator\">*<\/span> np<span class=\"token punctuation\">.<\/span>sin<span class=\"token punctuation\">(<\/span><span class=\"token number\">2<\/span> <span class=\"token operator\">*<\/span> np<span class=\"token punctuation\">.<\/span>pi <span class=\"token operator\">*<\/span> carrier_freq <span class=\"token operator\">*<\/span> t<span class=\"token punctuation\">)<\/span><br \/>\n    s <span class=\"token operator\">&#061;<\/span> s_I <span class=\"token operator\">&#043;<\/span> s_Q<br \/>\n    <span class=\"token keyword\">return<\/span> s<span class=\"token punctuation\">,<\/span> t<span class=\"token punctuation\">,<\/span> I<span class=\"token punctuation\">,<\/span> Q<\/p>\n<p><span class=\"token comment\"># \u751f\u6210\u968f\u673a\u6bd4\u7279<\/span><br \/>\nbits <span class=\"token operator\">&#061;<\/span> np<span class=\"token punctuation\">.<\/span>random<span class=\"token punctuation\">.<\/span>randint<span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">16<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">100<\/span><span class=\"token punctuation\">)<\/span><br \/>\nconstellation <span class=\"token operator\">&#061;<\/span> generate_16qam_constellation<span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><br \/>\ncarrier_freq <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">1000<\/span>  <span class=\"token comment\"># \u8f7d\u6ce2\u9891\u7387<\/span><br \/>\nsample_rate <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">10000<\/span>  <span class=\"token comment\"># \u91c7\u6837\u7387<\/span><\/p>\n<p><span class=\"token comment\"># \u751f\u6210QAM\u4fe1\u53f7<\/span><br \/>\nqam_signal<span class=\"token punctuation\">,<\/span> t<span class=\"token punctuation\">,<\/span> I<span class=\"token punctuation\">,<\/span> Q <span class=\"token operator\">&#061;<\/span> generate_16qam_signal<span class=\"token punctuation\">(<\/span>bits<span class=\"token punctuation\">,<\/span> constellation<span class=\"token punctuation\">,<\/span> carrier_freq<span class=\"token punctuation\">,<\/span> sample_rate<span class=\"token punctuation\">)<\/span><\/p>\n<p><span class=\"token comment\"># \u7ed8\u5236QAM\u4fe1\u53f7<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>figure<span class=\"token punctuation\">(<\/span>figsize<span class=\"token operator\">&#061;<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">12<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">6<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>subplot<span class=\"token punctuation\">(<\/span><span class=\"token number\">2<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>plot<span class=\"token punctuation\">(<\/span>t<span class=\"token punctuation\">,<\/span> qam_signal<span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>title<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;16-QAM Signal&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>xlabel<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Time (s)&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>ylabel<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Amplitude&#034;<\/span><span class=\"token punctuation\">)<\/span><\/p>\n<p>plt<span class=\"token punctuation\">.<\/span>subplot<span class=\"token punctuation\">(<\/span><span class=\"token number\">2<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">2<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>scatter<span class=\"token punctuation\">(<\/span>I<span class=\"token punctuation\">,<\/span> Q<span class=\"token punctuation\">,<\/span> marker<span class=\"token operator\">&#061;<\/span><span class=\"token string\">&#039;o&#039;<\/span><span class=\"token punctuation\">,<\/span> color<span class=\"token operator\">&#061;<\/span><span class=\"token string\">&#039;b&#039;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>title<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;16-QAM Constellation&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>xlabel<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;I&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>ylabel<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Q&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>grid<span class=\"token punctuation\">(<\/span><span class=\"token boolean\">True<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>show<span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><\/p>\n<h5>7.4.6.3 \u4e0b\u53d8\u9891<\/h5>\n<p>\u63a5\u4e0b\u6765&#xff0c;\u6211\u4eec\u5c06\u5bf9\u63a5\u6536\u5230\u7684QAM\u4fe1\u53f7\u8fdb\u884c\u4e0b\u53d8\u9891\u5904\u7406\u3002\u5047\u8bbe\u63a5\u6536\u5230\u7684\u4fe1\u53f7\u5df2\u7ecf\u5305\u542b\u4e86\u4e00\u4e9b\u566a\u58f0&#xff1a;<\/p>\n<p><span class=\"token comment\"># \u52a0\u5165AWGN\u566a\u58f0<\/span><br \/>\n<span class=\"token keyword\">def<\/span> <span class=\"token function\">add_awgn_noise<\/span><span class=\"token punctuation\">(<\/span>signal<span class=\"token punctuation\">,<\/span> snr<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">:<\/span><br \/>\n    signal_power <span class=\"token operator\">&#061;<\/span> np<span class=\"token punctuation\">.<\/span>mean<span class=\"token punctuation\">(<\/span>np<span class=\"token punctuation\">.<\/span><span class=\"token builtin\">abs<\/span><span class=\"token punctuation\">(<\/span>signal<span class=\"token punctuation\">)<\/span> <span class=\"token operator\">**<\/span> <span class=\"token number\">2<\/span><span class=\"token punctuation\">)<\/span><br \/>\n    noise_power <span class=\"token operator\">&#061;<\/span> signal_power <span class=\"token operator\">\/<\/span> <span class=\"token number\">10<\/span> <span class=\"token operator\">**<\/span> <span class=\"token punctuation\">(<\/span>snr <span class=\"token operator\">\/<\/span> <span class=\"token number\">10<\/span><span class=\"token punctuation\">)<\/span><br \/>\n    noise <span class=\"token operator\">&#061;<\/span> np<span class=\"token punctuation\">.<\/span>sqrt<span class=\"token punctuation\">(<\/span>noise_power<span class=\"token punctuation\">)<\/span> <span class=\"token operator\">*<\/span> np<span class=\"token punctuation\">.<\/span>random<span class=\"token punctuation\">.<\/span>normal<span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token builtin\">len<\/span><span class=\"token punctuation\">(<\/span>signal<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><br \/>\n    <span class=\"token keyword\">return<\/span> signal <span class=\"token operator\">&#043;<\/span> noise<\/p>\n<p><span class=\"token comment\"># \u751f\u6210\u5e26\u566a\u58f0\u7684QAM\u4fe1\u53f7<\/span><br \/>\nsnr <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">20<\/span>  <span class=\"token comment\"># \u4fe1\u566a\u6bd4<\/span><br \/>\nnoisy_signal <span class=\"token operator\">&#061;<\/span> add_awgn_noise<span class=\"token punctuation\">(<\/span>qam_signal<span class=\"token punctuation\">,<\/span> snr<span class=\"token punctuation\">)<\/span><\/p>\n<p><span class=\"token comment\"># \u4e0b\u53d8\u9891<\/span><br \/>\n<span class=\"token keyword\">def<\/span> <span class=\"token function\">downconvert<\/span><span class=\"token punctuation\">(<\/span>signal<span class=\"token punctuation\">,<\/span> carrier_freq<span class=\"token punctuation\">,<\/span> sample_rate<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">:<\/span><br \/>\n    t <span class=\"token operator\">&#061;<\/span> np<span class=\"token punctuation\">.<\/span>arange<span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token builtin\">len<\/span><span class=\"token punctuation\">(<\/span>signal<span class=\"token punctuation\">)<\/span> <span class=\"token operator\">\/<\/span> sample_rate<span class=\"token punctuation\">,<\/span> <span class=\"token number\">1<\/span> <span class=\"token operator\">\/<\/span> sample_rate<span class=\"token punctuation\">)<\/span><br \/>\n    r_I <span class=\"token operator\">&#061;<\/span> signal <span class=\"token operator\">*<\/span> np<span class=\"token punctuation\">.<\/span>cos<span class=\"token punctuation\">(<\/span><span class=\"token number\">2<\/span> <span class=\"token operator\">*<\/span> np<span class=\"token punctuation\">.<\/span>pi <span class=\"token operator\">*<\/span> carrier_freq <span class=\"token operator\">*<\/span> t<span class=\"token punctuation\">)<\/span><br \/>\n    r_Q <span class=\"token operator\">&#061;<\/span> signal <span class=\"token operator\">*<\/span> np<span class=\"token punctuation\">.<\/span>sin<span class=\"token punctuation\">(<\/span><span class=\"token number\">2<\/span> <span class=\"token operator\">*<\/span> np<span class=\"token punctuation\">.<\/span>pi <span class=\"token operator\">*<\/span> carrier_freq <span class=\"token operator\">*<\/span> t<span class=\"token punctuation\">)<\/span><br \/>\n    <span class=\"token keyword\">return<\/span> r_I<span class=\"token punctuation\">,<\/span> r_Q<\/p>\n<p><span class=\"token comment\"># \u4e0b\u53d8\u9891\u540e\u7684\u4fe1\u53f7<\/span><br \/>\nr_I<span class=\"token punctuation\">,<\/span> r_Q <span class=\"token operator\">&#061;<\/span> downconvert<span class=\"token punctuation\">(<\/span>noisy_signal<span class=\"token punctuation\">,<\/span> carrier_freq<span class=\"token punctuation\">,<\/span> sample_rate<span class=\"token punctuation\">)<\/span><\/p>\n<p><span class=\"token comment\"># \u7ed8\u5236\u4e0b\u53d8\u9891\u540e\u7684\u4fe1\u53f7<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>figure<span class=\"token punctuation\">(<\/span>figsize<span class=\"token operator\">&#061;<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">12<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">6<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>subplot<span class=\"token punctuation\">(<\/span><span class=\"token number\">2<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>plot<span class=\"token punctuation\">(<\/span>t<span class=\"token punctuation\">,<\/span> r_I<span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>title<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Downconverted In-Phase Signal&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>xlabel<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Time (s)&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>ylabel<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Amplitude&#034;<\/span><span class=\"token punctuation\">)<\/span><\/p>\n<p>plt<span class=\"token punctuation\">.<\/span>subplot<span class=\"token punctuation\">(<\/span><span class=\"token number\">2<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">2<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>plot<span class=\"token punctuation\">(<\/span>t<span class=\"token punctuation\">,<\/span> r_Q<span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>title<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Downconverted Quadrature Signal&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>xlabel<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Time (s)&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>ylabel<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Amplitude&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>show<span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><\/p>\n<h5>7.4.6.4 \u4f4e\u901a\u6ee4\u6ce2<\/h5>\n<p>\u4e0b\u53d8\u9891\u540e\u7684\u4fe1\u53f7\u9700\u8981\u901a\u8fc7\u4f4e\u901a\u6ee4\u6ce2\u5668\u6765\u6ee4\u9664\u9ad8\u9891\u566a\u58f0\u3002\u8fd9\u91cc\u6211\u4eec\u4f7f\u7528\u5df4\u7279\u6c83\u65af\u6ee4\u6ce2\u5668&#xff1a;<\/p>\n<p><span class=\"token comment\"># \u8bbe\u8ba1\u5df4\u7279\u6c83\u65af\u4f4e\u901a\u6ee4\u6ce2\u5668<\/span><br \/>\n<span class=\"token keyword\">def<\/span> <span class=\"token function\">design_butter_lowpass_filter<\/span><span class=\"token punctuation\">(<\/span>cutoff<span class=\"token punctuation\">,<\/span> fs<span class=\"token punctuation\">,<\/span> order<span class=\"token operator\">&#061;<\/span><span class=\"token number\">5<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">:<\/span><br \/>\n    nyquist <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">0.5<\/span> <span class=\"token operator\">*<\/span> fs<br \/>\n    normal_cutoff <span class=\"token operator\">&#061;<\/span> cutoff <span class=\"token operator\">\/<\/span> nyquist<br \/>\n    b<span class=\"token punctuation\">,<\/span> a <span class=\"token operator\">&#061;<\/span> butter<span class=\"token punctuation\">(<\/span>order<span class=\"token punctuation\">,<\/span> normal_cutoff<span class=\"token punctuation\">,<\/span> btype<span class=\"token operator\">&#061;<\/span><span class=\"token string\">&#039;low&#039;<\/span><span class=\"token punctuation\">,<\/span> analog<span class=\"token operator\">&#061;<\/span><span class=\"token boolean\">False<\/span><span class=\"token punctuation\">)<\/span><br \/>\n    <span class=\"token keyword\">return<\/span> b<span class=\"token punctuation\">,<\/span> a<\/p>\n<p><span class=\"token comment\"># \u5e94\u7528\u4f4e\u901a\u6ee4\u6ce2\u5668<\/span><br \/>\n<span class=\"token keyword\">def<\/span> <span class=\"token function\">apply_lowpass_filter<\/span><span class=\"token punctuation\">(<\/span>signal<span class=\"token punctuation\">,<\/span> b<span class=\"token punctuation\">,<\/span> a<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">:<\/span><br \/>\n    <span class=\"token keyword\">return<\/span> lfilter<span class=\"token punctuation\">(<\/span>b<span class=\"token punctuation\">,<\/span> a<span class=\"token punctuation\">,<\/span> signal<span class=\"token punctuation\">)<\/span><\/p>\n<p><span class=\"token comment\"># \u6ee4\u6ce2\u53c2\u6570<\/span><br \/>\ncutoff <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">500<\/span>  <span class=\"token comment\"># \u622a\u6b62\u9891\u7387<\/span><br \/>\nfs <span class=\"token operator\">&#061;<\/span> sample_rate  <span class=\"token comment\"># \u91c7\u6837\u7387<\/span><br \/>\nb<span class=\"token punctuation\">,<\/span> a <span class=\"token operator\">&#061;<\/span> design_butter_lowpass_filter<span class=\"token punctuation\">(<\/span>cutoff<span class=\"token punctuation\">,<\/span> fs<span class=\"token punctuation\">)<\/span><\/p>\n<p><span class=\"token comment\"># \u6ee4\u6ce2\u540e\u7684\u4fe1\u53f7<\/span><br \/>\nfiltered_r_I <span class=\"token operator\">&#061;<\/span> apply_lowpass_filter<span class=\"token punctuation\">(<\/span>r_I<span class=\"token punctuation\">,<\/span> b<span class=\"token punctuation\">,<\/span> a<span class=\"token punctuation\">)<\/span><br \/>\nfiltered_r_Q <span class=\"token operator\">&#061;<\/span> apply_lowpass_filter<span class=\"token punctuation\">(<\/span>r_Q<span class=\"token punctuation\">,<\/span> b<span class=\"token punctuation\">,<\/span> a<span class=\"token punctuation\">)<\/span><\/p>\n<p><span class=\"token comment\"># \u7ed8\u5236\u6ee4\u6ce2\u540e\u7684\u4fe1\u53f7<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>figure<span class=\"token punctuation\">(<\/span>figsize<span class=\"token operator\">&#061;<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">12<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">6<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>subplot<span class=\"token punctuation\">(<\/span><span class=\"token number\">2<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>plot<span class=\"token punctuation\">(<\/span>t<span class=\"token punctuation\">,<\/span> filtered_r_I<span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>title<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Filtered In-Phase Signal&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>xlabel<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Time (s)&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>ylabel<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Amplitude&#034;<\/span><span class=\"token punctuation\">)<\/span><\/p>\n<p>plt<span class=\"token punctuation\">.<\/span>subplot<span class=\"token punctuation\">(<\/span><span class=\"token number\">2<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">2<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>plot<span class=\"token punctuation\">(<\/span>t<span class=\"token punctuation\">,<\/span> filtered_r_Q<span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>title<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Filtered Quadrature Signal&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>xlabel<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Time (s)&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>ylabel<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Amplitude&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>show<span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><\/p>\n<h5>7.4.6.5 \u91c7\u6837<\/h5>\n<p>\u5728\u6ee4\u6ce2\u540e\u7684\u4fe1\u53f7\u4e2d&#xff0c;\u6211\u4eec\u9700\u8981\u5728\u5408\u9002\u7684\u65f6\u95f4\u70b9\u8fdb\u884c\u91c7\u6837\u3002\u901a\u5e38&#xff0c;\u91c7\u6837\u70b9\u9009\u62e9\u5728\u4fe1\u53f7\u7684\u5cf0\u503c\u9644\u8fd1&#xff0c;\u4ee5\u786e\u4fdd\u91c7\u6837\u7684\u51c6\u786e\u6027\u3002<\/p>\n<p><span class=\"token comment\"># \u91c7\u6837<\/span><br \/>\n<span class=\"token keyword\">def<\/span> <span class=\"token function\">sample_signal<\/span><span class=\"token punctuation\">(<\/span>filtered_signal<span class=\"token punctuation\">,<\/span> sample_rate<span class=\"token punctuation\">,<\/span> symbol_rate<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">:<\/span><br \/>\n    samples_per_symbol <span class=\"token operator\">&#061;<\/span> sample_rate <span class=\"token operator\">\/\/<\/span> symbol_rate<br \/>\n    sample_points <span class=\"token operator\">&#061;<\/span> np<span class=\"token punctuation\">.<\/span>arange<span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token builtin\">len<\/span><span class=\"token punctuation\">(<\/span>filtered_signal<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> samples_per_symbol<span class=\"token punctuation\">)<\/span><br \/>\n    <span class=\"token keyword\">return<\/span> filtered_signal<span class=\"token punctuation\">[<\/span>sample_points<span class=\"token punctuation\">]<\/span><\/p>\n<p><span class=\"token comment\"># \u7b26\u53f7\u7387<\/span><br \/>\nsymbol_rate <span class=\"token operator\">&#061;<\/span> <span class=\"token number\">100<\/span>  <span class=\"token comment\"># \u7b26\u53f7\u7387<\/span><\/p>\n<p><span class=\"token comment\"># \u91c7\u6837\u540e\u7684\u4fe1\u53f7<\/span><br \/>\nsampled_r_I <span class=\"token operator\">&#061;<\/span> sample_signal<span class=\"token punctuation\">(<\/span>filtered_r_I<span class=\"token punctuation\">,<\/span> sample_rate<span class=\"token punctuation\">,<\/span> symbol_rate<span class=\"token punctuation\">)<\/span><br \/>\nsampled_r_Q <span class=\"token operator\">&#061;<\/span> sample_signal<span class=\"token punctuation\">(<\/span>filtered_r_Q<span class=\"token punctuation\">,<\/span> sample_rate<span class=\"token punctuation\">,<\/span> symbol_rate<span class=\"token punctuation\">)<\/span><\/p>\n<p><span class=\"token comment\"># \u7ed8\u5236\u91c7\u6837\u540e\u7684\u4fe1\u53f7<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>figure<span class=\"token punctuation\">(<\/span>figsize<span class=\"token operator\">&#061;<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">12<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">6<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>subplot<span class=\"token punctuation\">(<\/span><span class=\"token number\">2<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>plot<span class=\"token punctuation\">(<\/span>sampled_r_I<span class=\"token punctuation\">,<\/span> label<span class=\"token operator\">&#061;<\/span><span class=\"token string\">&#034;Sampled I&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>title<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Sampled In-Phase Signal&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>xlabel<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Sample Index&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>ylabel<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Amplitude&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>legend<span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><\/p>\n<p>plt<span class=\"token punctuation\">.<\/span>subplot<span class=\"token punctuation\">(<\/span><span class=\"token number\">2<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">1<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">2<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>plot<span class=\"token punctuation\">(<\/span>sampled_r_Q<span class=\"token punctuation\">,<\/span> label<span class=\"token operator\">&#061;<\/span><span class=\"token string\">&#034;Sampled Q&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>title<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Sampled Quadrature Signal&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>xlabel<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Sample Index&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>ylabel<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Amplitude&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>legend<span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>show<span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><\/p>\n<h5>7.4.6.6 \u7b26\u53f7\u68c0\u6d4b<\/h5>\n<p>\u6700\u540e&#xff0c;\u6211\u4eec\u5c06\u91c7\u6837\u540e\u7684I\u548cQ\u5206\u91cf\u4e0e\u9884\u5b9a\u4e49\u7684\u661f\u5ea7\u56fe\u8fdb\u884c\u6bd4\u8f83&#xff0c;\u6062\u590d\u51fa\u539f\u59cb\u7684\u6570\u5b57\u4fe1\u606f\u3002<\/p>\n<p><span class=\"token comment\"># \u7b26\u53f7\u68c0\u6d4b<\/span><br \/>\n<span class=\"token keyword\">def<\/span> <span class=\"token function\">symbol_detection<\/span><span class=\"token punctuation\">(<\/span>sampled_I<span class=\"token punctuation\">,<\/span> sampled_Q<span class=\"token punctuation\">,<\/span> constellation<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">:<\/span><br \/>\n    detected_bits <span class=\"token operator\">&#061;<\/span> <span class=\"token punctuation\">[<\/span><span class=\"token punctuation\">]<\/span><br \/>\n    <span class=\"token keyword\">for<\/span> i<span class=\"token punctuation\">,<\/span> q <span class=\"token keyword\">in<\/span> <span class=\"token builtin\">zip<\/span><span class=\"token punctuation\">(<\/span>sampled_I<span class=\"token punctuation\">,<\/span> sampled_Q<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">:<\/span><br \/>\n        min_idx <span class=\"token operator\">&#061;<\/span> np<span class=\"token punctuation\">.<\/span>argmin<span class=\"token punctuation\">(<\/span>np<span class=\"token punctuation\">.<\/span><span class=\"token builtin\">abs<\/span><span class=\"token punctuation\">(<\/span>constellation <span class=\"token operator\">&#8211;<\/span> <span class=\"token punctuation\">(<\/span>i<span class=\"token punctuation\">,<\/span> q<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><br \/>\n        detected_bits<span class=\"token punctuation\">.<\/span>append<span class=\"token punctuation\">(<\/span>min_idx<span class=\"token punctuation\">)<\/span><br \/>\n    <span class=\"token keyword\">return<\/span> np<span class=\"token punctuation\">.<\/span>array<span class=\"token punctuation\">(<\/span>detected_bits<span class=\"token punctuation\">)<\/span><\/p>\n<p><span class=\"token comment\"># \u6062\u590d\u539f\u59cb\u6bd4\u7279<\/span><br \/>\ndetected_bits <span class=\"token operator\">&#061;<\/span> symbol_detection<span class=\"token punctuation\">(<\/span>sampled_r_I<span class=\"token punctuation\">,<\/span> sampled_r_Q<span class=\"token punctuation\">,<\/span> constellation<span class=\"token punctuation\">)<\/span><\/p>\n<p><span class=\"token comment\"># \u7ed8\u5236\u6062\u590d\u7684\u6bd4\u7279\u5e8f\u5217<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>figure<span class=\"token punctuation\">(<\/span>figsize<span class=\"token operator\">&#061;<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">12<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token number\">6<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>plot<span class=\"token punctuation\">(<\/span>detected_bits<span class=\"token punctuation\">,<\/span> label<span class=\"token operator\">&#061;<\/span><span class=\"token string\">&#034;Detected Bits&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>title<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Detected Bit Sequence&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>xlabel<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Sample Index&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>ylabel<span class=\"token punctuation\">(<\/span><span class=\"token string\">&#034;Bit Value&#034;<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>legend<span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><br \/>\nplt<span class=\"token punctuation\">.<\/span>show<span class=\"token punctuation\">(<\/span><span class=\"token punctuation\">)<\/span><\/p>\n<h4>7.4.7 QAM\u89e3\u8c03\u7684\u6027\u80fd\u8bc4\u4f30<\/h4>\n<p>\u4e3a\u4e86\u8bc4\u4f30QAM\u89e3\u8c03\u7684\u6027\u80fd&#xff0c;\u6211\u4eec\u53ef\u4ee5\u8ba1\u7b97\u8bef\u7801\u7387&#xff08;Bit Error Rate, BER&#xff09;\u3002\u8bef\u7801\u7387\u662f\u89e3\u8c03\u540e\u6062\u590d\u7684\u6bd4\u7279\u5e8f\u5217\u4e0e\u539f\u59cb\u6bd4\u7279\u5e8f\u5217\u4e4b\u95f4\u7684\u5dee\u5f02\u3002<\/p>\n<p><span class=\"token comment\"># \u8ba1\u7b97\u8bef\u7801\u7387<\/span><br \/>\n<span class=\"token keyword\">def<\/span> <span class=\"token function\">calculate_ber<\/span><span class=\"token punctuation\">(<\/span>original_bits<span class=\"token punctuation\">,<\/span> detected_bits<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">:<\/span><br \/>\n    errors <span class=\"token operator\">&#061;<\/span> np<span class=\"token punctuation\">.<\/span><span class=\"token builtin\">sum<\/span><span class=\"token punctuation\">(<\/span>original_bits <span class=\"token operator\">!&#061;<\/span> detected_bits<span class=\"token punctuation\">)<\/span><br \/>\n    ber <span class=\"token operator\">&#061;<\/span> errors <span class=\"token operator\">\/<\/span> <span class=\"token builtin\">len<\/span><span class=\"token punctuation\">(<\/span>original_bits<span class=\"token punctuation\">)<\/span><br \/>\n    <span class=\"token keyword\">return<\/span> ber<\/p>\n<p><span class=\"token comment\"># \u8ba1\u7b97\u8bef\u7801\u7387<\/span><br \/>\nber <span class=\"token operator\">&#061;<\/span> calculate_ber<span class=\"token punctuation\">(<\/span>bits<span class=\"token punctuation\">,<\/span> detected_bits<span class=\"token punctuation\">)<\/span><br \/>\n<span class=\"token keyword\">print<\/span><span class=\"token punctuation\">(<\/span><span class=\"token string-interpolation\"><span class=\"token string\">f&#034;Bit Error Rate (BER): <\/span><span class=\"token interpolation\"><span class=\"token punctuation\">{<\/span>ber<span class=\"token punctuation\">}<\/span><\/span><span class=\"token string\">&#034;<\/span><\/span><span class=\"token punctuation\">)<\/span><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/08\/20250815225944-689fbbe062334.jpg\" alt=\"\u5728\u8fd9\u91cc\u63d2\u5165\u56fe\u7247\u63cf\u8ff0\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u6587\u7ae0\u6d4f\u89c8\u9605\u8bfb121\u6b21\u3002QAM\u89e3\u8c03\u5219\u662f\u5c06\u63a5\u6536\u5230\u7684QAM\u4fe1\u53f7\u6062\u590d\u6210\u539f\u59cb\u7684\u6570\u5b57\u4fe1\u606f\u7684\u8fc7\u7a0b\u3002QAM\u89e3\u8c03\u7684\u57fa\u672c\u539f\u7406\u662f\u901a\u8fc7\u68c0\u6d4b\u63a5\u6536\u5230\u7684\u4fe1\u53f7\u7684\u632f\u5e45\u548c\u76f8\u4f4d\u6765\u6062\u590d\u539f\u59cb\u7684\u6570\u5b57\u4fe1\u606f\u3002QAM\u4fe1\u53f7\u53ef\u4ee5\u770b\u4f5c\u662f\u4e24\u4e2a\u6b63\u4ea4\u7684\u8f7d\u6ce2\u4fe1\u53f7\u7684\u53e0\u52a0\uff0c\u6bcf\u4e2a\u8f7d\u6ce2\u4fe1\u53f7\u5206\u522b\u643a\u5e26\u4e86\u4e0d\u540c\u7684\u4fe1\u606f\u3002\u661f\u5ea7\u56fe\u662fQAM\u8c03\u5236\u5668\u548c\u89e3\u8c03\u5668\u4e4b\u95f4\u7684\u4e00\u79cd\u7ea6\u5b9a\uff0c\u8868\u793a\u4e86\u6bcf\u4e2a\u7b26\u53f7\u5bf9\u5e94\u7684I\u548cQ\u5206\u91cf\u7684\u7ec4\u5408\u3002\u901a\u5e38\uff0c\u91c7\u6837\u70b9\u9009\u62e9\u5728\u4fe1\u53f7\u7684\u5cf0\u503c\u9644\u8fd1\uff0c\u4ee5\u786e\u4fdd\u91c7\u6837\u7684\u51c6\u786e\u6027\u3002\u6700\u540e\uff0c\u6211\u4eec\u5c06\u91c7\u6837\u540e\u7684I\u548cQ\u5206\u91cf\u4e0e\u9884\u5b9a\u4e49\u7684\u661f\u5ea7\u56fe\u8fdb\u884c\u6bd4\u8f83\uff0c\u6062\u590d\u51fa\u539f\u59cb\u7684\u6570\u5b57\u4fe1\u606f\u3002\u4e0b\u53d8\u9891\u662fQAM\u89e3\u8c03\u7684\u7b2c\u4e00\u6b65\uff0c\u5176\u76ee\u7684\u662f\u5c06\u63a5\u6536\u5230\u7684\u9ad8\u9891\u4fe1\u53f7\u3002<\/p>\n","protected":false},"author":2,"featured_media":58223,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[5138,2710,43,78,44],"topic":[],"class_list":["post-58224","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-server","tag-5138","tag-2710","tag-43","tag-78","tag-44"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v20.3 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>\u65e0\u7ebf\u901a\u4fe1\u57fa\u7840\uff1a\u8c03\u5236\u4e0e\u89e3\u8c03\u6280\u672f_\uff0844\uff09.7.4\u6b63\u4ea4\u5e45\u5ea6\u89e3\u8c03(QAM\u89e3\u8c03) - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.wsisp.com\/helps\/58224.html\" \/>\n<meta property=\"og:locale\" content=\"zh_CN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"\u65e0\u7ebf\u901a\u4fe1\u57fa\u7840\uff1a\u8c03\u5236\u4e0e\u89e3\u8c03\u6280\u672f_\uff0844\uff09.7.4\u6b63\u4ea4\u5e45\u5ea6\u89e3\u8c03(QAM\u89e3\u8c03) - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3\" \/>\n<meta property=\"og:description\" content=\"\u6587\u7ae0\u6d4f\u89c8\u9605\u8bfb121\u6b21\u3002QAM\u89e3\u8c03\u5219\u662f\u5c06\u63a5\u6536\u5230\u7684QAM\u4fe1\u53f7\u6062\u590d\u6210\u539f\u59cb\u7684\u6570\u5b57\u4fe1\u606f\u7684\u8fc7\u7a0b\u3002QAM\u89e3\u8c03\u7684\u57fa\u672c\u539f\u7406\u662f\u901a\u8fc7\u68c0\u6d4b\u63a5\u6536\u5230\u7684\u4fe1\u53f7\u7684\u632f\u5e45\u548c\u76f8\u4f4d\u6765\u6062\u590d\u539f\u59cb\u7684\u6570\u5b57\u4fe1\u606f\u3002QAM\u4fe1\u53f7\u53ef\u4ee5\u770b\u4f5c\u662f\u4e24\u4e2a\u6b63\u4ea4\u7684\u8f7d\u6ce2\u4fe1\u53f7\u7684\u53e0\u52a0\uff0c\u6bcf\u4e2a\u8f7d\u6ce2\u4fe1\u53f7\u5206\u522b\u643a\u5e26\u4e86\u4e0d\u540c\u7684\u4fe1\u606f\u3002\u661f\u5ea7\u56fe\u662fQAM\u8c03\u5236\u5668\u548c\u89e3\u8c03\u5668\u4e4b\u95f4\u7684\u4e00\u79cd\u7ea6\u5b9a\uff0c\u8868\u793a\u4e86\u6bcf\u4e2a\u7b26\u53f7\u5bf9\u5e94\u7684I\u548cQ\u5206\u91cf\u7684\u7ec4\u5408\u3002\u901a\u5e38\uff0c\u91c7\u6837\u70b9\u9009\u62e9\u5728\u4fe1\u53f7\u7684\u5cf0\u503c\u9644\u8fd1\uff0c\u4ee5\u786e\u4fdd\u91c7\u6837\u7684\u51c6\u786e\u6027\u3002\u6700\u540e\uff0c\u6211\u4eec\u5c06\u91c7\u6837\u540e\u7684I\u548cQ\u5206\u91cf\u4e0e\u9884\u5b9a\u4e49\u7684\u661f\u5ea7\u56fe\u8fdb\u884c\u6bd4\u8f83\uff0c\u6062\u590d\u51fa\u539f\u59cb\u7684\u6570\u5b57\u4fe1\u606f\u3002\u4e0b\u53d8\u9891\u662fQAM\u89e3\u8c03\u7684\u7b2c\u4e00\u6b65\uff0c\u5176\u76ee\u7684\u662f\u5c06\u63a5\u6536\u5230\u7684\u9ad8\u9891\u4fe1\u53f7\u3002\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.wsisp.com\/helps\/58224.html\" \/>\n<meta property=\"og:site_name\" content=\"\u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3\" \/>\n<meta property=\"article:published_time\" content=\"2025-08-15T22:59:46+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/08\/20250815225944-689fbbe062334.jpg\" \/>\n<meta name=\"author\" content=\"admin\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u4f5c\u8005\" \/>\n\t<meta name=\"twitter:data1\" content=\"admin\" \/>\n\t<meta name=\"twitter:label2\" content=\"\u9884\u8ba1\u9605\u8bfb\u65f6\u95f4\" \/>\n\t<meta name=\"twitter:data2\" content=\"5 \u5206\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.wsisp.com\/helps\/58224.html\",\"url\":\"https:\/\/www.wsisp.com\/helps\/58224.html\",\"name\":\"\u65e0\u7ebf\u901a\u4fe1\u57fa\u7840\uff1a\u8c03\u5236\u4e0e\u89e3\u8c03\u6280\u672f_\uff0844\uff09.7.4\u6b63\u4ea4\u5e45\u5ea6\u89e3\u8c03(QAM\u89e3\u8c03) - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3\",\"isPartOf\":{\"@id\":\"https:\/\/www.wsisp.com\/helps\/#website\"},\"datePublished\":\"2025-08-15T22:59:46+00:00\",\"dateModified\":\"2025-08-15T22:59:46+00:00\",\"author\":{\"@id\":\"https:\/\/www.wsisp.com\/helps\/#\/schema\/person\/358e386c577a3ab51c4493330a20ad41\"},\"breadcrumb\":{\"@id\":\"https:\/\/www.wsisp.com\/helps\/58224.html#breadcrumb\"},\"inLanguage\":\"zh-Hans\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.wsisp.com\/helps\/58224.html\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.wsisp.com\/helps\/58224.html#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"\u9996\u9875\",\"item\":\"https:\/\/www.wsisp.com\/helps\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"\u65e0\u7ebf\u901a\u4fe1\u57fa\u7840\uff1a\u8c03\u5236\u4e0e\u89e3\u8c03\u6280\u672f_\uff0844\uff09.7.4\u6b63\u4ea4\u5e45\u5ea6\u89e3\u8c03(QAM\u89e3\u8c03)\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.wsisp.com\/helps\/#website\",\"url\":\"https:\/\/www.wsisp.com\/helps\/\",\"name\":\"\u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3\",\"description\":\"\u9999\u6e2f\u670d\u52a1\u5668_\u9999\u6e2f\u4e91\u670d\u52a1\u5668\u8d44\u8baf_\u670d\u52a1\u5668\u5e2e\u52a9\u6587\u6863_\u670d\u52a1\u5668\u6559\u7a0b\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/www.wsisp.com\/helps\/?s={search_term_string}\"},\"query-input\":\"required name=search_term_string\"}],\"inLanguage\":\"zh-Hans\"},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.wsisp.com\/helps\/#\/schema\/person\/358e386c577a3ab51c4493330a20ad41\",\"name\":\"admin\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"zh-Hans\",\"@id\":\"https:\/\/www.wsisp.com\/helps\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/gravatar.wp-china-yes.net\/avatar\/?s=96&d=mystery\",\"contentUrl\":\"https:\/\/gravatar.wp-china-yes.net\/avatar\/?s=96&d=mystery\",\"caption\":\"admin\"},\"sameAs\":[\"http:\/\/wp.wsisp.com\"],\"url\":\"https:\/\/www.wsisp.com\/helps\/author\/admin\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"\u65e0\u7ebf\u901a\u4fe1\u57fa\u7840\uff1a\u8c03\u5236\u4e0e\u89e3\u8c03\u6280\u672f_\uff0844\uff09.7.4\u6b63\u4ea4\u5e45\u5ea6\u89e3\u8c03(QAM\u89e3\u8c03) - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.wsisp.com\/helps\/58224.html","og_locale":"zh_CN","og_type":"article","og_title":"\u65e0\u7ebf\u901a\u4fe1\u57fa\u7840\uff1a\u8c03\u5236\u4e0e\u89e3\u8c03\u6280\u672f_\uff0844\uff09.7.4\u6b63\u4ea4\u5e45\u5ea6\u89e3\u8c03(QAM\u89e3\u8c03) - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3","og_description":"\u6587\u7ae0\u6d4f\u89c8\u9605\u8bfb121\u6b21\u3002QAM\u89e3\u8c03\u5219\u662f\u5c06\u63a5\u6536\u5230\u7684QAM\u4fe1\u53f7\u6062\u590d\u6210\u539f\u59cb\u7684\u6570\u5b57\u4fe1\u606f\u7684\u8fc7\u7a0b\u3002QAM\u89e3\u8c03\u7684\u57fa\u672c\u539f\u7406\u662f\u901a\u8fc7\u68c0\u6d4b\u63a5\u6536\u5230\u7684\u4fe1\u53f7\u7684\u632f\u5e45\u548c\u76f8\u4f4d\u6765\u6062\u590d\u539f\u59cb\u7684\u6570\u5b57\u4fe1\u606f\u3002QAM\u4fe1\u53f7\u53ef\u4ee5\u770b\u4f5c\u662f\u4e24\u4e2a\u6b63\u4ea4\u7684\u8f7d\u6ce2\u4fe1\u53f7\u7684\u53e0\u52a0\uff0c\u6bcf\u4e2a\u8f7d\u6ce2\u4fe1\u53f7\u5206\u522b\u643a\u5e26\u4e86\u4e0d\u540c\u7684\u4fe1\u606f\u3002\u661f\u5ea7\u56fe\u662fQAM\u8c03\u5236\u5668\u548c\u89e3\u8c03\u5668\u4e4b\u95f4\u7684\u4e00\u79cd\u7ea6\u5b9a\uff0c\u8868\u793a\u4e86\u6bcf\u4e2a\u7b26\u53f7\u5bf9\u5e94\u7684I\u548cQ\u5206\u91cf\u7684\u7ec4\u5408\u3002\u901a\u5e38\uff0c\u91c7\u6837\u70b9\u9009\u62e9\u5728\u4fe1\u53f7\u7684\u5cf0\u503c\u9644\u8fd1\uff0c\u4ee5\u786e\u4fdd\u91c7\u6837\u7684\u51c6\u786e\u6027\u3002\u6700\u540e\uff0c\u6211\u4eec\u5c06\u91c7\u6837\u540e\u7684I\u548cQ\u5206\u91cf\u4e0e\u9884\u5b9a\u4e49\u7684\u661f\u5ea7\u56fe\u8fdb\u884c\u6bd4\u8f83\uff0c\u6062\u590d\u51fa\u539f\u59cb\u7684\u6570\u5b57\u4fe1\u606f\u3002\u4e0b\u53d8\u9891\u662fQAM\u89e3\u8c03\u7684\u7b2c\u4e00\u6b65\uff0c\u5176\u76ee\u7684\u662f\u5c06\u63a5\u6536\u5230\u7684\u9ad8\u9891\u4fe1\u53f7\u3002","og_url":"https:\/\/www.wsisp.com\/helps\/58224.html","og_site_name":"\u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3","article_published_time":"2025-08-15T22:59:46+00:00","og_image":[{"url":"https:\/\/www.wsisp.com\/helps\/wp-content\/uploads\/2025\/08\/20250815225944-689fbbe062334.jpg"}],"author":"admin","twitter_card":"summary_large_image","twitter_misc":{"\u4f5c\u8005":"admin","\u9884\u8ba1\u9605\u8bfb\u65f6\u95f4":"5 \u5206"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/www.wsisp.com\/helps\/58224.html","url":"https:\/\/www.wsisp.com\/helps\/58224.html","name":"\u65e0\u7ebf\u901a\u4fe1\u57fa\u7840\uff1a\u8c03\u5236\u4e0e\u89e3\u8c03\u6280\u672f_\uff0844\uff09.7.4\u6b63\u4ea4\u5e45\u5ea6\u89e3\u8c03(QAM\u89e3\u8c03) - \u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3","isPartOf":{"@id":"https:\/\/www.wsisp.com\/helps\/#website"},"datePublished":"2025-08-15T22:59:46+00:00","dateModified":"2025-08-15T22:59:46+00:00","author":{"@id":"https:\/\/www.wsisp.com\/helps\/#\/schema\/person\/358e386c577a3ab51c4493330a20ad41"},"breadcrumb":{"@id":"https:\/\/www.wsisp.com\/helps\/58224.html#breadcrumb"},"inLanguage":"zh-Hans","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.wsisp.com\/helps\/58224.html"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/www.wsisp.com\/helps\/58224.html#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"\u9996\u9875","item":"https:\/\/www.wsisp.com\/helps"},{"@type":"ListItem","position":2,"name":"\u65e0\u7ebf\u901a\u4fe1\u57fa\u7840\uff1a\u8c03\u5236\u4e0e\u89e3\u8c03\u6280\u672f_\uff0844\uff09.7.4\u6b63\u4ea4\u5e45\u5ea6\u89e3\u8c03(QAM\u89e3\u8c03)"}]},{"@type":"WebSite","@id":"https:\/\/www.wsisp.com\/helps\/#website","url":"https:\/\/www.wsisp.com\/helps\/","name":"\u7f51\u7855\u4e92\u8054\u5e2e\u52a9\u4e2d\u5fc3","description":"\u9999\u6e2f\u670d\u52a1\u5668_\u9999\u6e2f\u4e91\u670d\u52a1\u5668\u8d44\u8baf_\u670d\u52a1\u5668\u5e2e\u52a9\u6587\u6863_\u670d\u52a1\u5668\u6559\u7a0b","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.wsisp.com\/helps\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"zh-Hans"},{"@type":"Person","@id":"https:\/\/www.wsisp.com\/helps\/#\/schema\/person\/358e386c577a3ab51c4493330a20ad41","name":"admin","image":{"@type":"ImageObject","inLanguage":"zh-Hans","@id":"https:\/\/www.wsisp.com\/helps\/#\/schema\/person\/image\/","url":"https:\/\/gravatar.wp-china-yes.net\/avatar\/?s=96&d=mystery","contentUrl":"https:\/\/gravatar.wp-china-yes.net\/avatar\/?s=96&d=mystery","caption":"admin"},"sameAs":["http:\/\/wp.wsisp.com"],"url":"https:\/\/www.wsisp.com\/helps\/author\/admin"}]}},"_links":{"self":[{"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/posts\/58224","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/comments?post=58224"}],"version-history":[{"count":0,"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/posts\/58224\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/media\/58223"}],"wp:attachment":[{"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/media?parent=58224"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/categories?post=58224"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/tags?post=58224"},{"taxonomy":"topic","embeddable":true,"href":"https:\/\/www.wsisp.com\/helps\/wp-json\/wp\/v2\/topic?post=58224"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}