qpsk_viterbi_soft.rar_matlab_Soft!_matlab例程_数值算法/人工智能下载-pudn.com

<html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta charset="utf-8"> <meta name="generator" content="pdf2htmlEX"> <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"> <link rel="stylesheet" href="https://static.pudn.com/base/css/base.min.css"> <link rel="stylesheet" href="https://static.pudn.com/base/css/fancy.min.css"> <link rel="stylesheet" href="https://static.pudn.com/prod/directory_preview_static/626ce4b81fd0a5795280596b/raw.css"> <script src="https://static.pudn.com/base/js/compatibility.min.js"></script> <script src="https://static.pudn.com/base/js/pdf2htmlEX.min.js"></script> <script> try{ pdf2htmlEX.defaultViewer = new pdf2htmlEX.Viewer({}); }catch(e){} </script> <title></title> </head> <body> <div id="sidebar" style="display: none"> <div id="outline"> </div> </div> <div id="pf1" class="pf w0 h0" data-page-no="1"><div class="pc pc1 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/626ce4b81fd0a5795280596b/bg1.jpg"><div class="t m0 x1 h2 y1 ff1 fs0 fc0 sc0 ls0 ws0">4</div><div class="t m0 x1 h3 y2 ff2 fs1 fc0 sc0 ls0 ws0">Modulation<span class="_ _0"> </span>and<span class="_ _0"> </span>Coding</div><div class="t m0 x1 h4 y3 ff2 fs2 fc0 sc0 ls1 ws0">The<span class="_ _1"> </span>L<span class="_ _2"></span>TE<span class="_ _1"> </span>(Long<span class="_ _1"> </span>T<span class="_ _2"></span>erm<span class="_ _1"> </span>Evolution)<span class="_ _1"> </span>do<span class="_ _3"></span>wnlink<span class="_ _1"> </span>PHY<span class="_ _1"> </span>(Physical<span class="_ _1"> </span>Layer)<span class="_ _1"> </span>chain<span class="_ _1"> </span>can<span class="_ _1"> </span>be<span class="_ _1"> </span>vie<span class="_ _3"></span>wed<span class="_ _1"> </span>as<span class="_ _1"> </span>the</div><div class="t m0 x1 h4 y4 ff2 fs2 fc0 sc0 ls1 ws0">combination<span class="_ _4"> </span>of<span class="_ _4"> </span>processing<span class="_ _4"> </span>applied<span class="_ _4"> </span>to<span class="_ _4"> </span>the<span class="_ _4"> </span>Do<span class="_ _3"></span>wnlink<span class="_ _4"> </span>Shared<span class="_ _4"> </span>Channel<span class="_ _4"> </span>(DLSCH)<span class="_ _4"> </span>and<span class="_ _4"> </span>Physical</div><div class="t m0 x1 h4 y5 ff2 fs2 fc0 sc0 ls1 ws0">Do<span class="_ _3"></span>wnlink<span class="_ _4"> </span>Shared<span class="_ _1"> </span>Channel<span class="_ _4"> </span>(PDSCH).<span class="_ _1"> </span>DLSCH<span class="_ _4"> </span>processing<span class="_ _1"> </span>is<span class="_ _4"> </span>also<span class="_ _1"> </span>known<span class="_ _1"> </span>as<span class="_ _4"> </span>Do<span class="_ _3"></span>wnlink<span class="_ _1"> </span>Trans-</div><div class="t m0 x1 h4 y6 ff2 fs2 fc0 sc0 ls1 ws0">port<span class="_ _5"> </span>Channel<span class="_ _5"> </span>(T<span class="_ _3"></span>rCH)<span class="_ _5"> </span>processing.<span class="_ _5"> </span>It<span class="_ _5"> </span>includes<span class="_ _5"> </span>steps<span class="_ _5"> </span>in<span class="_ _3"></span>v<span class="_ _3"></span>olving<span class="_ _5"> </span>Cyclic<span class="_ _5"> </span>Redundanc<span class="_ _3"></span>y<span class="_ _5"> </span>Check<span class="_ _5"> </span>(CRC)</div><div class="t m0 x1 h4 y7 ff2 fs2 fc0 sc0 ls1 ws0">code<span class="_ _5"> </span>attachment,<span class="_ _5"> </span>data<span class="_ _5"> </span>subblock<span class="_ _1"> </span>processing,<span class="_ _5"> </span>channel<span class="_ _5"> </span>coding<span class="_ _5"> </span>based<span class="_ _5"> </span>on<span class="_ _5"> </span>turbo<span class="_ _5"> </span>coders,<span class="_ _1"> </span>rate<span class="_ _5"> </span>match-</div><div class="t m0 x1 h4 y8 ff2 fs2 fc0 sc0 ls1 ws0">ing,<span class="_ _4"> </span>Hybrid<span class="_ _1"> </span>Automatic<span class="_ _4"> </span>Repeat<span class="_ _4"> </span>Request<span class="_ _1"> </span>(HARQ)<span class="_ _4"> </span>processing,<span class="_ _4"> </span>and<span class="_ _4"> </span>the<span class="_ _1"> </span>reconstruction<span class="_ _4"> </span>of<span class="_ _4"> </span>code-</div><div class="t m0 x1 h4 y9 ff2 fs2 fc0 sc0 ls1 ws0">words.<span class="_ _5"> </span>The<span class="_ _6"> </span>code<span class="_ _3"></span>words<span class="_ _6"> </span>are<span class="_ _5"> </span>inputs<span class="_ _6"> </span>for<span class="_ _5"> </span>the<span class="_ _5"> </span>PDSCH<span class="_ _6"> </span>processing,<span class="_ _5"> </span>which<span class="_ _5"> </span>in<span class="_ _3"></span>v<span class="_ _3"></span>olv<span class="_ _3"></span>es<span class="_ _6"> </span>scrambling,<span class="_ _5"> </span>mod-</div><div class="t m0 x1 h4 ya ff2 fs2 fc0 sc0 ls2 ws0">ulation,<span class="_ _4"> </span>multi-antenna<span class="_ _4"> </span>Multiple<span class="_ _4"> </span>Input<span class="_ _4"> </span>Multiple<span class="_ _1"> </span>Output<span class="_ _4"> </span>(MIMO)<span class="_ _4"> </span>processing,<span class="_ _4"> </span>time<span class="_ _7"></span>–<span class="_ _7"></span>frequenc<span class="_ _3"></span>y</div><div class="t m0 x1 h4 yb ff2 fs2 fc0 sc0 ls2 ws0">resource<span class="_ _4"> </span>mapping,<span class="_ _4"> </span>and<span class="_ _4"> </span>Orthogonal<span class="_ _4"> </span>Frequenc<span class="_ _3"></span>y<span class="_ _4"> </span>Di<span class="_ _3"></span>vision<span class="_ _4"> </span>Multiple<span class="_ _3"></span>xing<span class="_ _4"> </span>(OFDM)<span class="_ _4"> </span>transmission.</div><div class="t m0 x1 h4 yc ff2 fs2 fc0 sc0 ls1 ws0">W<span class="_ _2"></span>e<span class="_ _4"> </span>hav<span class="_ _3"></span>e<span class="_ _4"> </span>subdi<span class="_ _3"></span>vided<span class="_ _4"> </span>the<span class="_ _1"> </span>components<span class="_ _4"> </span>of<span class="_ _4"> </span>this<span class="_ _4"> </span>two-step<span class="_ _4"> </span>DLSCH<span class="_ _1"> </span>and<span class="_ _4"> </span>PDSCH<span class="_ _4"> </span>processing<span class="_ _4"> </span>chain</div><div class="t m0 x1 h4 yd ff2 fs2 fc0 sc0 ls2 ws0">into<span class="_ _1"> </span>three<span class="_ _1"> </span>se<span class="_ _3"></span>gments,<span class="_ _1"> </span>which<span class="_ _1"> </span>are<span class="_ _1"> </span>discussed<span class="_ _1"> </span>in<span class="_ _1"> </span>the<span class="_ _5"> </span>next<span class="_ _1"> </span>three<span class="_ _1"> </span>chapters.</div><div class="t m0 x2 h4 ye ff2 fs2 fc0 sc0 ls1 ws0">In<span class="_ _1"> </span>this<span class="_ _4"> </span>chapter<span class="_ _3"></span>,<span class="_ _1"> </span>we<span class="_ _4"> </span>examine<span class="_ _1"> </span>the<span class="_ _4"> </span>modulation<span class="_ _1"> </span>and<span class="_ _4"> </span>coding<span class="_ _1"> </span>schemes<span class="_ _4"> </span>used<span class="_ _1"> </span>in<span class="_ _4"> </span>the<span class="_ _1"> </span>L<span class="_ _2"></span>TE<span class="_ _4"> </span>standard.</div><div class="t m0 x1 h4 yf ff2 fs2 fc0 sc0 ls1 ws0">These<span class="_ _1"> </span>include<span class="_ _4"> </span>all<span class="_ _1"> </span>the<span class="_ _1"> </span>combined<span class="_ _4"> </span>DLSCH<span class="_ _1"> </span>and<span class="_ _1"> </span>PDSCH<span class="_ _4"> </span>processing<span class="_ _1"> </span>steps,<span class="_ _1"> </span>excluding<span class="_ _4"> </span>the<span class="_ _1"> </span>MIMO</div><div class="t m0 x1 h4 y10 ff2 fs2 fc0 sc0 ls2 ws0">and<span class="_ _1"> </span>OFDM<span class="_ _1"> </span>operations.<span class="_ _1"> </span>Discussion<span class="_ _1"> </span>regarding<span class="_ _1"> </span>OFDM<span class="_ _1"> </span>and<span class="_ _1"> </span>MIMO<span class="_ _4"> </span>is<span class="_ _1"> </span>presented<span class="_ _1"> </span>in<span class="_ _1"> </span>the<span class="_ _1"> </span>next<span class="_ _1"> </span>two</div><div class="t m0 x1 h4 y11 ff2 fs2 fc0 sc0 ls2 ws0">chapters.<span class="_ _6"> </span>First,<span class="_ _6"> </span>we<span class="_ _6"> </span>will<span class="_ _6"> </span>examine<span class="_ _6"> </span>the<span class="_ _6"> </span>rst<span class="_ _5"> </span>couple<span class="_ _6"> </span>of<span class="_ _6"> </span>operations<span class="_ _6"> </span>performed<span class="_ _6"> </span>in<span class="_ _5"> </span>PDSCH<span class="_ _6"> </span>processing,</div><div class="t m0 x1 h4 y12 ff2 fs2 fc0 sc0 ls1 ws0">including<span class="_ _1"> </span>scrambling<span class="_ _1"> </span>and<span class="_ _1"> </span>modulation.<span class="_ _1"> </span>Then<span class="_ _1"> </span>we<span class="_ _1"> </span>will<span class="_ _1"> </span>examine<span class="_ _1"> </span>T<span class="_ _3"></span>rCH<span class="_ _1"> </span>processing,<span class="_ _1"> </span>comprising<span class="_ _1"> </span>a</div><div class="t m0 x1 h4 y13 ff2 fs2 fc0 sc0 ls1 ws0">series<span class="_ _4"> </span>of<span class="_ _4"> </span>operations<span class="_ _4"> </span>that<span class="_ _4"> </span>map<span class="_ _4"> </span>logical<span class="_ _4"> </span>channels<span class="_ _1"> </span>and<span class="_ _4"> </span>user<span class="_ _4"> </span>bit<span class="_ _4"> </span>payload<span class="_ _4"> </span>to<span class="_ _4"> </span>codew<span class="_ _3"></span>ords,<span class="_ _4"> </span>which<span class="_ _4"> </span>are</div><div class="t m0 x1 h4 y14 ff2 fs2 fc0 sc0 ls1 ws0">passed<span class="_ _1"> </span>to<span class="_ _1"> </span>the<span class="_ _1"> </span>shared<span class="_ _1"> </span>physical<span class="_ _5"> </span>channel.</div><div class="t m0 x2 h4 y15 ff2 fs2 fc0 sc0 ls2 ws0">W<span class="_ _2"></span>e<span class="_ _8"> </span>will<span class="_ _4"> </span>create<span class="_ _8"> </span>MA<span class="_ _2"></span>TLAB</div><div class="t m0 x3 h4 y16 ff2 fs2 fc0 sc0 ls0 ws0">®</div><div class="t m0 x4 h4 y15 ff2 fs2 fc0 sc0 ls2 ws0">programs<span class="_ _4"> </span>that<span class="_ _8"> </span>completely<span class="_ _8"> </span>specify<span class="_ _8"> </span>the<span class="_ _4"> </span>TrCH<span class="_ _4"> </span>processing<span class="_ _8"> </span>in<span class="_ _4"> </span>the</div><div class="t m0 x1 h4 y17 ff2 fs2 fc0 sc0 ls2 ws0">transmitter<span class="_ _5"> </span>and<span class="_ _1"> </span>the<span class="_ _5"> </span>receiver<span class="_ _2"></span>.<span class="_ _1"> </span>W<span class="_ _2"></span>e<span class="_ _1"> </span>will<span class="_ _5"> </span>use<span class="_ _1"> </span>the<span class="_ _5"> </span>MA<span class="_ _2"></span>TLAB<span class="_ _5"> </span>functions<span class="_ _1"> </span>to<span class="_ _5"> </span>study<span class="_ _1"> </span>the<span class="_ _5"> </span>effects<span class="_ _5"> </span>of<span class="_ _1"> </span>dif<span class="_ _3"></span>fer<span class="_ _3"></span>-</div><div class="t m0 x1 h4 y18 ff2 fs2 fc0 sc0 ls1 ws0">ent<span class="_ _1"> </span>modulation<span class="_ _4"> </span>schemes<span class="_ _1"> </span>and<span class="_ _1"> </span>different<span class="_ _1"> </span>coding<span class="_ _4"> </span>rates<span class="_ _1"> </span>on<span class="_ _1"> </span>the<span class="_ _4"> </span>Bit<span class="_ _1"> </span>Error<span class="_ _1"> </span>Rate<span class="_ _1"> </span>(BER)<span class="_ _4"> </span>performance</div><div class="t m0 x1 h4 y19 ff2 fs2 fc0 sc0 ls1 ws0">with<span class="_ _6"> </span>an<span class="_ _5"> </span>Additi<span class="_ _3"></span>ve<span class="_ _6"> </span>White<span class="_ _6"> </span>Gaussian<span class="_ _6"> </span>Noise<span class="_ _5"> </span>(A<span class="_ _2"></span>WGN)<span class="_ _6"> </span>channel<span class="_ _5"> </span>model.<span class="_ _6"> </span>These<span class="_ _5"> </span>operations<span class="_ _6"> </span>completely</div><div class="t m0 x1 h4 y1a ff2 fs2 fc0 sc0 ls1 ws0">specify<span class="_ _9"> </span>ho<span class="_ _3"></span>w<span class="_ _9"> </span>user<span class="_ _9"> </span>data<span class="_ _9"> </span>bits<span class="_ _9"> </span>are<span class="_ _9"> </span>processed<span class="_ _9"> </span>to<span class="_ _9"> </span>produce<span class="_ _9"> </span>the<span class="_ _9"> </span>input<span class="_ _9"> </span>symbols<span class="_ _9"> </span>for<span class="_ _9"> </span>the<span class="_ _9"> </span>subsequent</div><div class="t m0 x1 h4 y1b ff2 fs2 fc0 sc0 ls1 ws0">MIMO<span class="_ _1"> </span>and<span class="_ _5"> </span>OFDM<span class="_ _1"> </span>functional<span class="_ _1"> </span>blocks<span class="_ _1"> </span>for<span class="_ _5"> </span>transmission.<span class="_ _1"> </span>Details<span class="_ _1"> </span>of<span class="_ _a"> </span>MIMO<span class="_ _a"> </span>and<span class="_ _a"> </span>OFDM<span class="_ _1"> </span>are<span class="_ _a"> </span>then</div><div class="t m0 x1 h4 y1c ff2 fs2 fc0 sc0 ls2 ws0">examined<span class="_ _a"> </span>in<span class="_ _1"> </span>the<span class="_ _a"> </span>next<span class="_ _1"> </span>two<span class="_ _a"> </span>chapters.</div><div class="t m0 x1 h5 y1d ff3 fs3 fc0 sc0 ls0 ws0">Understanding<span class="_ _6"> </span>LTE<span class="_ _5"> </span>with<span class="_ _5"> </span>MA<span class="_ _3"></span>TLAB</div><div class="t m0 x3 h5 y1e ff3 fs3 fc0 sc0 ls0 ws0">®</div><div class="t m0 x5 h5 y1d ff3 fs3 fc0 sc0 ls0 ws0">:<span class="_ _5"> </span>F<span class="_ _3"></span>r<span class="_ _b"></span>om<span class="_ _5"> </span>Mathematical<span class="_ _5"> </span>Modeling<span class="_ _6"> </span>to<span class="_ _5"> </span>Simulation<span class="_ _5"> </span>and<span class="_ _5"> </span>Prototyping<span class="ff2 ls3">,<span class="_ _6"> </span>First<span class="_ _5"> </span>Edition.</span></div><div class="t m0 x1 h5 y1f ff2 fs3 fc0 sc0 ls4 ws0">Houman<span class="_ _5"> </span>Zarrinkoub<span class="_ _b"></span>.</div><div class="t m0 x1 h5 y20 ff2 fs3 fc0 sc0 ls0 ws0">©<span class="_ _5"> </span>2014<span class="_ _6"> </span>John<span class="_ _5"> </span>Wiley<span class="_ _6"> </span>&<span class="_ _5"> </span>Sons,<span class="_ _5"> </span>Ltd.<span class="_ _5"> </span>Published<span class="_ _6"> </span>2014<span class="_ _5"> </span>by<span class="_ _5"> </span>John<span class="_ _5"> </span>Wile<span class="_ _3"></span>y<span class="_ _6"> </span>&<span class="_ _5"> </span>Sons,<span class="_ _5"> </span>Ltd.</div></div><div class="pi" data-data='{"ctm":[1.961964,0.000000,0.000000,1.961964,0.000000,0.000000]}'></div></div> </body> </html>

<div id="pf2" class="pf w0 h0" data-page-no="2"><div class="pc pc2 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/626ce4b81fd0a5795280596b/bg2.jpg"><div class="t m0 x6 h6 y21 ff1 fs4 fc0 sc0 ls0 ws0">72<span class="_ _c"> </span><span class="ff2 ls5">Understanding<span class="_ _a"> </span>L<span class="_ _2"></span>TE<span class="_ _a"> </span>with<span class="_ _a"> </span>MA<span class="_ _2"></span>TLAB</span></div><div class="t m0 x7 h6 y22 ff2 fs4 fc0 sc0 ls0 ws0">®</div><div class="t m0 x6 h7 y23 ff1 fs5 fc1 sc0 ls0 ws0">4.1<span class="_ _d"> </span>Modulation<span class="_ _4"> </span>Schemes<span class="_ _4"> </span>of<span class="_ _4"> </span>L<span class="_ _2"></span>TE</div><div class="t m0 x6 h4 y24 ff2 fs2 fc1 sc0 ls1 ws0">The<span class="_ _8"> </span>modulation<span class="_ _8"> </span>schemes<span class="_ _9"> </span>used<span class="_ _8"> </span>in<span class="_ _8"> </span>the<span class="_ _8"> </span>L<span class="_ _2"></span>TE<span class="_ _8"> </span>standard<span class="_ _9"> </span>include<span class="_ _8"> </span>QPSK<span class="_ _8"> </span>(Quadrature<span class="_ _8"> </span>Phase<span class="_ _9"> </span>Shift</div><div class="t m0 x6 h4 y25 ff2 fs2 fc1 sc0 ls1 ws0">K<span class="_ _3"></span>eying),<span class="_ _8"> </span>16QAM<span class="_ _8"> </span>(Quadrature<span class="_ _8"> </span>Amplitude<span class="_ _8"> </span>Modulation),<span class="_ _9"> </span>and<span class="_ _8"> </span>64QAM.<span class="_ _8"> </span>Figure<span class="_ _8"> </span>4.1<span class="_ _8"> </span>shows<span class="_ _8"> </span>the</div><div class="t m0 x6 h4 y26 ff2 fs2 fc1 sc0 ls1 ws0">constellation<span class="_ _a"> </span>diagrams<span class="_ _1"> </span>of<span class="_ _1"> </span>these<span class="_ _1"> </span>three<span class="_ _1"> </span>modulation<span class="_ _1"> </span>schemes.</div><div class="t m0 x1 h4 y27 ff2 fs2 fc1 sc0 ls1 ws0">In<span class="_ _5"> </span>the<span class="_ _6"> </span>case<span class="_ _5"> </span>of<span class="_ _5"> </span>QPSK<span class="_ _5"> </span>modulation,<span class="_ _5"> </span>each<span class="_ _5"> </span>modulation<span class="_ _5"> </span>symbol<span class="_ _5"> </span>can<span class="_ _5"> </span>hav<span class="_ _b"></span>e<span class="_ _5"> </span>one<span class="_ _5"> </span>of<span class="_ _5"> </span>four<span class="_ _5"> </span>different<span class="_ _6"> </span>val-</div><div class="t m0 x6 h4 y28 ff2 fs2 fc1 sc0 ls1 ws0">ues,<span class="_ _a"> </span>which<span class="_ _a"> </span>are<span class="_ _1"> </span>mapped<span class="_ _a"> </span>to<span class="_ _1"> </span>four<span class="_ _a"> </span>different<span class="_ _5"> </span>positions<span class="_ _1"> </span>in<span class="_ _a"> </span>the<span class="_ _1"> </span>constellation<span class="_ _a"> </span>diagram.<span class="_ _a"> </span>QPSK<span class="_ _1"> </span>needs<span class="_ _a"> </span>2</div><div class="t m0 x6 h4 y29 ff2 fs2 fc1 sc0 ls1 ws0">bits<span class="_ _5"> </span>to<span class="_ _6"> </span>encode<span class="_ _5"> </span>each<span class="_ _5"> </span>of<span class="_ _5"> </span>its<span class="_ _5"> </span>four<span class="_ _6"> </span>different<span class="_ _6"> </span>modulation<span class="_ _5"> </span>symbols.<span class="_ _5"> </span>The<span class="_ _5"> </span>16QAM<span class="_ _5"> </span>modulation<span class="_ _6"> </span>inv<span class="_ _b"></span>olves</div><div class="t m0 x6 h4 y2a ff2 fs2 fc1 sc0 ls1 ws0">using<span class="_ _6"> </span>16<span class="_ _5"> </span>different<span class="_ _6"> </span>signaling<span class="_ _5"> </span>choices<span class="_ _6"> </span>and<span class="_ _5"> </span>thus<span class="_ _5"> </span>utilizes<span class="_ _5"> </span>4<span class="_ _6"> </span>bits<span class="_ _5"> </span>of<span class="_ _5"> </span>information<span class="_ _6"> </span>to<span class="_ _5"> </span>encode<span class="_ _5"> </span>each<span class="_ _6"> </span>mod-</div><div class="t m0 x6 h4 y2b ff2 fs2 fc1 sc0 ls1 ws0">ulation<span class="_ _4"> </span>symbol.<span class="_ _1"> </span>The<span class="_ _4"> </span>64QAM<span class="_ _4"> </span>modulation<span class="_ _1"> </span>inv<span class="_ _b"></span>olves<span class="_ _4"> </span>64<span class="_ _1"> </span>different<span class="_ _1"> </span>possible<span class="_ _4"> </span>signaling<span class="_ _4"> </span>v<span class="_ _b"></span>alues<span class="_ _4"> </span>and</div><div class="t m0 x6 h4 y2c ff2 fs2 fc1 sc0 ls2 ws0">thus<span class="_ _a"> </span>requires<span class="_ _1"> </span>6<span class="_ _1"> </span>bits<span class="_ _1"> </span>to<span class="_ _1"> </span>represent<span class="_ _a"> </span>a<span class="_ _1"> </span>single<span class="_ _1"> </span>modulation<span class="_ _1"> </span>symbol.</div><div class="t m0 x1 h4 y2d ff2 fs2 fc1 sc0 ls2 ws0">The<span class="_ _4"> </span>a<span class="_ _3"></span>v<span class="_ _3"></span>ailability<span class="_ _4"> </span>of<span class="_ _4"> </span>multiple<span class="_ _4"> </span>modulation<span class="_ _1"> </span>schemes<span class="_ _4"> </span>is<span class="_ _4"> </span>instrumental<span class="_ _4"> </span>in<span class="_ _4"> </span>implementing<span class="_ _4"> </span>adapti<span class="_ _3"></span>ve</div><div class="t m0 x6 h4 y2e ff2 fs2 fc1 sc0 ls1 ws0">modulation<span class="_ _8"> </span>based<span class="_ _9"> </span>on<span class="_ _9"> </span>channel<span class="_ _8"> </span>conditions.<span class="_ _9"> </span>When<span class="_ _8"> </span>the<span class="_ _9"> </span>radio<span class="_ _9"> </span>link<span class="_ _8"> </span>is<span class="_ _9"> </span>relati<span class="_ _3"></span>vely<span class="_ _8"> </span>clean<span class="_ _e"> </span>–<span class="_ _e"> </span>that<span class="_ _8"> </span>is,</div><div class="t m0 x6 h4 y2f ff2 fs2 fc1 sc0 ls2 ws0">the<span class="_ _f"> </span>Signal-to-Noise<span class="_ _f"> </span>Ratio<span class="_ _f"> </span>(SNR)<span class="_ _f"> </span>is<span class="_ _f"> </span>relati<span class="_ _3"></span>vely<span class="_ _9"> </span>high<span class="_"> </span>–<span class="_"> </span>we<span class="_ _f"> </span>can<span class="_ _f"> </span>use<span class="_ _f"> </span>modulation<span class="_ _f"> </span>schemes<span class="_ _f"> </span>of</div><div class="t m0 x6 h4 y30 ff2 fs2 fc1 sc0 ls1 ws0">denser<span class="_ _1"> </span>constellations,<span class="_ _4"> </span>such<span class="_ _a"> </span>as<span class="_ _4"> </span>64QAM.<span class="_ _1"> </span>In<span class="_ _1"> </span>such<span class="_ _4"> </span>a<span class="_ _a"> </span>case,<span class="_ _4"> </span>sending<span class="_ _1"> </span>a<span class="_ _1"> </span>single<span class="_ _1"> </span>symbol<span class="_ _4"> </span>results<span class="_ _1"> </span>in<span class="_ _1"> </span>the</div><div class="t m0 x6 h4 y31 ff2 fs2 fc1 sc0 ls1 ws0">transmission<span class="_ _8"> </span>of<span class="_ _9"> </span>6<span class="_ _9"> </span>bits<span class="_ _8"> </span>and<span class="_ _9"> </span>therefore<span class="_ _9"> </span>can<span class="_ _8"> </span>increase<span class="_ _9"> </span>our<span class="_ _9"> </span>throughput.<span class="_ _9"> </span>Ho<span class="_ _b"></span>wever<span class="_ _b"></span>,<span class="_ _9"> </span>as<span class="_ _8"> </span>the<span class="_ _9"> </span>channel</div><div class="t m0 x6 h4 y32 ff2 fs2 fc1 sc0 ls1 ws0">becomes<span class="_ _1"> </span>noisier<span class="_ _b"></span>,<span class="_ _1"> </span>we<span class="_ _1"> </span>should<span class="_ _1"> </span>resort<span class="_ _1"> </span>to<span class="_ _1"> </span>using<span class="_ _1"> </span>modulation<span class="_ _1"> </span>schemes<span class="_ _1"> </span>with<span class="_ _1"> </span>more<span class="_ _1"> </span>intersymbol<span class="_ _1"> </span>sepa-</div><div class="t m0 x6 h4 y33 ff2 fs2 fc1 sc0 ls1 ws0">ration,<span class="_ _4"> </span>such<span class="_ _1"> </span>as<span class="_ _4"> </span>QPSK.<span class="_ _1"> </span>This<span class="_ _4"> </span>in<span class="_ _1"> </span>turn<span class="_ _4"> </span>will<span class="_ _1"> </span>reduce<span class="_ _4"> </span>the<span class="_ _1"> </span>number<span class="_ _4"> </span>of<span class="_ _4"> </span>bits<span class="_ _1"> </span>per<span class="_ _4"> </span>sample<span class="_ _1"> </span>and<span class="_ _4"> </span>reduce<span class="_ _1"> </span>the</div><div class="t m0 x6 h4 y34 ff2 fs2 fc1 sc0 ls1 ws0">throughput.</div><div class="t m0 x8 h8 y35 ff4 fs6 fc2 sc0 ls0 ws0">0</div><div class="t m0 x9 h8 y36 ff4 fs6 fc2 sc0 ls0 ws0">0</div><div class="t m0 xa h9 y37 ff4 fs7 fc2 sc0 ls0 ws0">QPSK</div><div class="t m0 xb h9 y38 ff4 fs7 fc2 sc0 ls0 ws0">QAM16</div><div class="t m0 xc h9 y39 ff4 fs7 fc2 sc0 ls0 ws0">QAM64</div><div class="t m0 xd h8 y3a ff4 fs6 fc2 sc0 ls0 ws0">0.5</div><div class="t m0 xe h8 y3b ff4 fs6 fc2 sc0 ls0 ws0">0.5</div><div class="t m0 xf h8 y3c ff5 fs6 fc2 sc0 ls0 ws0">−<span class="ff4">0.5</span></div><div class="t m0 x10 h8 y3d ff5 fs6 fc2 sc0 ls0 ws0">−<span class="ff4">0.5</span></div><div class="t m0 x11 h8 y3c ff5 fs6 fc2 sc0 ls0 ws0">−<span class="ff4">1.5</span></div><div class="t m0 x10 h8 y3e ff5 fs6 fc2 sc0 ls0 ws0">−<span class="ff4">1.5</span></div><div class="t m0 xe h8 y3f ff4 fs6 fc2 sc0 ls0 ws0">1.5</div><div class="t m0 x12 h8 y40 ff4 fs6 fc2 sc0 ls0 ws0">Scatter Plot</div><div class="t m0 x13 h8 y41 ff4 fs6 fc2 sc0 ls0 ws0">Scatter Plot</div><div class="t m0 x14 h8 y42 ff4 fs6 fc2 sc0 ls0 ws0">1</div><div class="t m0 x8 h8 y43 ff4 fs6 fc2 sc0 ls0 ws0">1</div><div class="t m0 x15 h8 y44 ff5 fs6 fc2 sc0 ls0 ws0">−<span class="ff4">1</span></div><div class="t m0 x16 h8 y45 ff4 fs6 fc2 sc0 ls0 ws0">0<span class="_ _10"> </span>0.5</div><div class="t m0 x17 h8 y46 ff5 fs6 fc2 sc0 ls0 ws0">−<span class="ff4">0.5<span class="_ _11"></span><span class="ff5">−<span class="ff4">1.5</span></span></span></div><div class="t m0 x18 h8 y45 ff4 fs6 fc2 sc0 ls0 ws0">1</div><div class="t m0 x19 h8 y46 ff5 fs6 fc2 sc0 ls0 ws0">−<span class="ff4">1</span></div><div class="t m0 x1a h8 y47 ff5 fs6 fc2 sc0 ls0 ws0">−<span class="ff4">1</span></div><div class="t m0 x1b h8 y48 ff4 fs6 fc2 sc0 ls0 ws0">0</div><div class="t m0 x1c h8 y49 ff4 fs6 fc2 sc0 ls0 ws0">0<span class="_ _12"> </span>0.5</div><div class="t m0 x1d h8 y4a ff4 fs6 fc2 sc0 ls0 ws0">0.5</div><div class="t m0 x1e h8 y4b ff5 fs6 fc2 sc0 ls0 ws0">−<span class="ff4">0.5</span></div><div class="t m0 x1f h8 y4c ff5 fs6 fc2 sc0 ls0 ws0">−<span class="ff4">0.5</span></div><div class="t m0 x1b h8 y4b ff5 fs6 fc2 sc0 ls0 ws0">−<span class="ff4">1.5</span></div><div class="t m0 x20 h8 y49 ff4 fs6 fc2 sc0 ls0 ws0">1.5</div><div class="t m0 x1f h8 y4d ff5 fs6 fc2 sc0 ls0 ws0">−<span class="ff4">1.5</span></div><div class="t m0 x1d h8 y4e ff4 fs6 fc2 sc0 ls0 ws0">1.5</div><div class="t m0 x21 h8 y4f ff4 fs6 fc2 sc0 ls0 ws0">Scatter Plot</div><div class="t m0 x22 h8 y50 ff4 fs6 fc2 sc0 ls0 ws0">1</div><div class="t m0 x1b h8 y51 ff4 fs6 fc2 sc0 ls0 ws0">1</div><div class="t m0 x23 h8 y52 ff5 fs6 fc2 sc0 ls0 ws0">−<span class="ff4">1</span></div><div class="t m0 x24 h8 y53 ff5 fs6 fc2 sc0 ls0 ws0">−<span class="ff4">1</span></div><div class="t m0 x25 h8 y54 ff4 fs6 fc2 sc0 ls0 ws0">0</div><div class="t m0 x26 h8 y55 ff4 fs6 fc2 sc0 ls0 ws0">0.5</div><div class="t m0 x27 h8 y56 ff5 fs6 fc2 sc0 ls0 ws0">−<span class="ff4">0.5</span></div><div class="t m0 x27 h8 y57 ff5 fs6 fc2 sc0 ls0 ws0">−<span class="ff4">1.5</span></div><div class="t m0 x26 h8 y58 ff4 fs6 fc2 sc0 ls0 ws0">1.5</div><div class="t m0 x25 h8 y59 ff4 fs6 fc2 sc0 ls0 ws0">1</div><div class="t m0 x28 h8 y5a ff5 fs6 fc2 sc0 ls0 ws0">−<span class="ff4">1</span></div><div class="t m0 x29 h6 y5b ff1 fs4 fc0 sc0 ls5 ws0">Figure<span class="_ _5"> </span>4.1<span class="_ _13"> </span><span class="ff2 ls0">Constellation<span class="_ _a"> </span>diagrams<span class="_ _a"> </span>of<span class="_ _a"> </span>QPSK,<span class="_ _a"> </span>16QAM,<span class="_ _a"> </span>and<span class="_ _a"> </span>64QAM</span></div></div><div class="pi" data-data='{"ctm":[1.961964,0.000000,0.000000,1.961964,0.000000,0.000000]}'></div></div>

<div id="pf3" class="pf w0 h0" data-page-no="3"><div class="pc pc3 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/626ce4b81fd0a5795280596b/bg3.jpg"><div class="t m0 x1 h6 y5c ff2 fs4 fc0 sc0 ls5 ws0">Modulation<span class="_ _a"> </span>and<span class="_ _a"> </span>Coding<span class="_ _14"> </span><span class="ff1 ls0">73</span></div><div class="t m0 x2a h6 y5d ff1 fs4 fc0 sc0 ls0 ws0">T<span class="_ _2"></span>able<span class="_ _a"> </span>4.1<span class="_ _13"> </span><span class="ff2 ls5">Mapping<span class="_ _a"> </span>for<span class="_ _a"> </span>an<span class="_ _a"> </span>L<span class="_ _2"></span>TE<span class="_ _a"> </span>QPSK<span class="_ _a"> </span>modulator</span></div><div class="t m0 x2b h6 y5e ff2 fs4 fc0 sc0 ls6 ws0">Payload<span class="_ _5"> </span>bit<span class="_ _a"> </span>pattern<span class="_ _a"> </span>(2<span class="_ _6"> </span>bits)<span class="_ _15"> </span><span class="ls5">Modulated<span class="_ _a"> </span>symbol</span></div><div class="t m0 x2c h6 y5f ff2 fs4 fc0 sc0 ls0 ws0">In-phase<span class="_ _a"> </span>(I)<span class="_ _d"> </span>Quadrature<span class="_ _5"> </span>(Q)</div><div class="t m0 x2b h6 y60 ff2 fs4 fc0 sc0 ls0 ws0">00</div><div class="t m0 x2d ha y61 ff2 fs8 fc0 sc0 ls0 ws0">1</div><div class="t m0 x2e hb y60 ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x2f hc y62 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x30 ha y63 ff2 fs8 fc0 sc0 ls0 ws0">2</div><div class="t m0 x31 ha y61 ff2 fs8 fc0 sc0 ls0 ws0">1</div><div class="t m0 x32 hb y60 ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x33 hc y62 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x34 ha y63 ff2 fs8 fc0 sc0 ls0 ws0">2</div><div class="t m0 x2b h6 y64 ff2 fs4 fc0 sc0 ls0 ws0">01</div><div class="t m0 x2d ha y65 ff2 fs8 fc0 sc0 ls0 ws0">1</div><div class="t m0 x2e hb y64 ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x2f hc y66 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x30 ha y67 ff2 fs8 fc0 sc0 ls0 ws0">2</div><div class="t m0 x35 hd y65 ff6 fs8 fc0 sc0 ls0 ws0">−<span class="ff2">1</span></div><div class="t m0 x36 hb y64 ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x37 hc y66 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x21 ha y67 ff2 fs8 fc0 sc0 ls0 ws0">2</div><div class="t m0 x2b h6 y68 ff2 fs4 fc0 sc0 ls0 ws0">10</div><div class="t m0 x38 hd y69 ff6 fs8 fc0 sc0 ls0 ws0">−<span class="ff2">1</span></div><div class="t m0 x39 hb y68 ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x3a hc y6a ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x3b ha y6b ff2 fs8 fc0 sc0 ls0 ws0">2</div><div class="t m0 x31 ha y69 ff2 fs8 fc0 sc0 ls0 ws0">1</div><div class="t m0 x32 hb y68 ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x33 hc y6a ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x34 ha y6b ff2 fs8 fc0 sc0 ls0 ws0">2</div><div class="t m0 x2b h6 y6c ff2 fs4 fc0 sc0 ls0 ws0">11</div><div class="t m0 x38 hd y6d ff6 fs8 fc0 sc0 ls0 ws0">−<span class="ff2">1</span></div><div class="t m0 x39 hb y6c ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x3a hc y6e ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x3b ha y6f ff2 fs8 fc0 sc0 ls0 ws0">2</div><div class="t m0 x35 hd y6d ff6 fs8 fc0 sc0 ls0 ws0">−<span class="ff2">1</span></div><div class="t m0 x36 hb y6c ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x37 hc y6e ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x21 ha y6f ff2 fs8 fc0 sc0 ls0 ws0">2</div><div class="t m0 x2a h6 y70 ff1 fs4 fc0 sc0 ls0 ws0">T<span class="_ _2"></span>able<span class="_ _a"> </span>4.2<span class="_ _13"> </span><span class="ff2 ls5">Mapping<span class="_ _a"> </span>for<span class="_ _a"> </span>an<span class="_ _a"> </span>L<span class="_ _2"></span>TE<span class="_ _a"> </span>16QAM<span class="_ _a"> </span>modulator</span></div><div class="t m0 x2b h6 y71 ff2 fs4 fc0 sc0 ls6 ws0">Payload<span class="_ _5"> </span>bit<span class="_ _a"> </span>pattern<span class="_ _a"> </span>(4<span class="_ _6"> </span>bits)<span class="_ _15"> </span><span class="ls5">Modulated<span class="_ _a"> </span>symbol</span></div><div class="t m0 x2c h6 y72 ff2 fs4 fc0 sc0 ls0 ws0">In-phase<span class="_ _a"> </span>(I)<span class="_ _d"> </span>Quadrature<span class="_ _5"> </span>(Q)</div><div class="t m0 x2b h6 y73 ff2 fs4 fc0 sc0 ls0 ws0">0000</div><div class="t m0 x3c ha y74 ff2 fs8 fc0 sc0 ls0 ws0">1</div><div class="t m0 x3d hb y73 ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x39 hc y75 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x3e ha y76 ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x3f ha y74 ff2 fs8 fc0 sc0 ls0 ws0">1</div><div class="t m0 x40 hb y73 ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x36 hc y75 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x41 ha y76 ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x2b h6 y77 ff2 fs4 fc0 sc0 ls0 ws0">0001</div><div class="t m0 x3c ha y78 ff2 fs8 fc0 sc0 ls0 ws0">1</div><div class="t m0 x3d hb y77 ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x39 hc y79 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x3e ha y7a ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x3f ha y78 ff2 fs8 fc0 sc0 ls0 ws0">3</div><div class="t m0 x40 hb y77 ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x36 hc y79 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x41 ha y7a ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x2b h6 y7b ff2 fs4 fc0 sc0 ls0 ws0">0010</div><div class="t m0 x3c ha y7c ff2 fs8 fc0 sc0 ls0 ws0">3</div><div class="t m0 x3d hb y7b ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x39 hc y7d ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x3e ha y7e ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x3f ha y7c ff2 fs8 fc0 sc0 ls0 ws0">1</div><div class="t m0 x40 hb y7b ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x36 hc y7d ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x41 ha y7e ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x2b h6 y7f ff2 fs4 fc0 sc0 ls0 ws0">0011</div><div class="t m0 x3c ha y80 ff2 fs8 fc0 sc0 ls0 ws0">3</div><div class="t m0 x3d hb y7f ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x39 hc y81 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x3e ha y82 ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x3f ha y80 ff2 fs8 fc0 sc0 ls0 ws0">3</div><div class="t m0 x40 hb y7f ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x36 hc y81 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x41 ha y82 ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x2b h6 y83 ff2 fs4 fc0 sc0 ls0 ws0">0100</div><div class="t m0 x3c ha y84 ff2 fs8 fc0 sc0 ls0 ws0">1</div><div class="t m0 x3d hb y83 ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x39 hc y85 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x3e ha y86 ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x42 hd y84 ff6 fs8 fc0 sc0 ls0 ws0">−<span class="ff2">1</span></div><div class="t m0 x43 hb y83 ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x1e hc y85 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x44 ha y86 ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x2b h6 y87 ff2 fs4 fc0 sc0 ls0 ws0">0101</div><div class="t m0 x3c ha y88 ff2 fs8 fc0 sc0 ls0 ws0">1</div><div class="t m0 x3d hb y87 ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x39 hc y89 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x3e ha y8a ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x42 hd y88 ff6 fs8 fc0 sc0 ls0 ws0">−<span class="ff2">3</span></div><div class="t m0 x43 hb y87 ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x1e hc y89 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x44 ha y8a ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x2b h6 y8b ff2 fs4 fc0 sc0 ls0 ws0">0110</div><div class="t m0 x3c ha y8c ff2 fs8 fc0 sc0 ls0 ws0">3</div><div class="t m0 x3d hb y8b ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x39 hc y8d ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x3e ha y8e ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x42 hd y8c ff6 fs8 fc0 sc0 ls0 ws0">−<span class="ff2">1</span></div><div class="t m0 x43 hb y8b ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x1e hc y8d ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x44 ha y8e ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x2b h6 y8f ff2 fs4 fc0 sc0 ls0 ws0">0111</div><div class="t m0 x3c ha y90 ff2 fs8 fc0 sc0 ls0 ws0">3</div><div class="t m0 x3d hb y8f ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x39 hc y91 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x3e ha y92 ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x42 hd y90 ff6 fs8 fc0 sc0 ls0 ws0">−<span class="ff2">3</span></div><div class="t m0 x43 hb y8f ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x1e hc y91 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x44 ha y92 ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x2b h6 y93 ff2 fs4 fc0 sc0 ls0 ws0">1000</div><div class="t m0 x45 hd y94 ff6 fs8 fc0 sc0 ls0 ws0">−<span class="ff2">1</span></div><div class="t m0 x46 hb y93 ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x47 hc y95 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x48 ha y96 ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x3f ha y94 ff2 fs8 fc0 sc0 ls0 ws0">1</div><div class="t m0 x40 hb y93 ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x36 hc y95 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x41 ha y96 ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x2b h6 y97 ff2 fs4 fc0 sc0 ls0 ws0">1001</div><div class="t m0 x45 hd y98 ff6 fs8 fc0 sc0 ls0 ws0">−<span class="ff2">1</span></div><div class="t m0 x46 hb y97 ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x47 hc y99 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x48 ha y9a ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x3f ha y98 ff2 fs8 fc0 sc0 ls0 ws0">3</div><div class="t m0 x40 hb y97 ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x36 hc y99 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x41 ha y9a ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x2b h6 y9b ff2 fs4 fc0 sc0 ls0 ws0">1010</div><div class="t m0 x45 hd y9c ff6 fs8 fc0 sc0 ls0 ws0">−<span class="ff2">3</span></div><div class="t m0 x46 hb y9b ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x47 hc y9d ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x48 ha y9e ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x3f ha y9c ff2 fs8 fc0 sc0 ls0 ws0">1</div><div class="t m0 x40 hb y9b ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x36 hc y9d ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x41 ha y9e ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x2b h6 y9f ff2 fs4 fc0 sc0 ls0 ws0">1011</div><div class="t m0 x45 hd ya0 ff6 fs8 fc0 sc0 ls0 ws0">−<span class="ff2">3</span></div><div class="t m0 x46 hb y9f ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x47 hc ya1 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x48 ha ya2 ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x3f ha ya0 ff2 fs8 fc0 sc0 ls0 ws0">3</div><div class="t m0 x40 hb y9f ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x36 hc ya1 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x41 ha ya2 ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x2b h6 ya3 ff2 fs4 fc0 sc0 ls0 ws0">1100</div><div class="t m0 x45 hd ya4 ff6 fs8 fc0 sc0 ls0 ws0">−<span class="ff2">1</span></div><div class="t m0 x46 hb ya3 ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x47 hc ya5 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x48 ha ya6 ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x42 hd ya4 ff6 fs8 fc0 sc0 ls0 ws0">−<span class="ff2">1</span></div><div class="t m0 x43 hb ya3 ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x1e hc ya5 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x44 ha ya6 ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x2b h6 ya7 ff2 fs4 fc0 sc0 ls0 ws0">1101</div><div class="t m0 x45 hd ya8 ff6 fs8 fc0 sc0 ls0 ws0">−<span class="ff2">1</span></div><div class="t m0 x46 hb ya7 ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x47 hc ya9 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x48 ha yaa ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x42 hd ya8 ff6 fs8 fc0 sc0 ls0 ws0">−<span class="ff2">3</span></div><div class="t m0 x43 hb ya7 ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x1e hc ya9 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x44 ha yaa ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x2b h6 yab ff2 fs4 fc0 sc0 ls0 ws0">1110</div><div class="t m0 x45 hd yac ff6 fs8 fc0 sc0 ls0 ws0">−<span class="ff2">3</span></div><div class="t m0 x46 hb yab ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x47 hc yad ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x48 ha yae ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x42 hd yac ff6 fs8 fc0 sc0 ls0 ws0">−<span class="ff2">1</span></div><div class="t m0 x43 hb yab ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x1e hc yad ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x44 ha yae ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x2b h6 yaf ff2 fs4 fc0 sc0 ls0 ws0">1111</div><div class="t m0 x45 hd yb0 ff6 fs8 fc0 sc0 ls0 ws0">−<span class="ff2">3</span></div><div class="t m0 x46 hb yaf ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x47 hc yb1 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x48 ha yb2 ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x42 hd yb0 ff6 fs8 fc0 sc0 ls0 ws0">−<span class="ff2">3</span></div><div class="t m0 x43 hb yaf ff6 fs4 fc0 sc0 ls0 ws0">∕</div><div class="t m0 x1e hc yb1 ff7 fs8 fc0 sc0 ls0 ws0">√</div><div class="t m0 x44 ha yb2 ff2 fs8 fc0 sc0 ls7 ws0">10</div><div class="t m0 x2 h4 yb3 ff2 fs2 fc1 sc0 ls1 ws0">The<span class="_ _9"> </span>L<span class="_ _2"></span>TE<span class="_ _9"> </span>modulation<span class="_ _9"> </span>mappers,<span class="_ _9"> </span>which<span class="_ _9"> </span>specify<span class="_ _9"> </span>how<span class="_ _8"> </span>the<span class="_ _9"> </span>modulation<span class="_ _f"> </span>symbols<span class="_ _9"> </span>are<span class="_ _9"> </span>assigned</div><div class="t m0 x1 h4 yb4 ff2 fs2 fc1 sc0 ls1 ws0">to<span class="_ _8"> </span>each<span class="_ _8"> </span>bit<span class="_ _8"> </span>sequence,<span class="_ _8"> </span>are<span class="_ _8"> </span>shown<span class="_ _8"> </span>in<span class="_ _8"> </span>T<span class="_ _2"></span>able<span class="_ _8"> </span>4.1<span class="_ _8"> </span>for<span class="_ _9"> </span>QPSK<span class="_ _8"> </span>and<span class="_ _8"> </span>in<span class="_ _8"> </span>T<span class="_ _2"></span>able<span class="_ _8"> </span>4.2<span class="_ _8"> </span>for<span class="_ _8"> </span>16QAM.<span class="_ _9"> </span>Due</div><div class="t m0 x1 h4 yb5 ff2 fs2 fc1 sc0 ls1 ws0">to<span class="_ _4"> </span>its<span class="_ _4"> </span>large<span class="_ _4"> </span>size,<span class="_ _4"> </span>we<span class="_ _4"> </span>refer<span class="_ _4"> </span>the<span class="_ _4"> </span>reader<span class="_ _4"> </span>to<span class="_ _4"> </span>Reference<span class="_ _4"> </span>[1]<span class="_ _4"> </span>for<span class="_ _4"> </span>the<span class="_ _8"> </span>standard<span class="_ _4"> </span>document<span class="_ _4"> </span>on<span class="_ _4"> </span>64QAM</div><div class="t m0 x1 h4 yb6 ff2 fs2 fc1 sc0 ls1 ws0">modulation<span class="_ _a"> </span>mapping.</div><div class="t m0 x2 h4 yb7 ff2 fs2 fc1 sc0 ls1 ws0">W<span class="_ _2"></span>e<span class="_ _1"> </span>note<span class="_ _a"> </span>that<span class="_ _1"> </span>the<span class="_ _1"> </span>mapping<span class="_ _1"> </span>of<span class="_ _a"> </span>bits<span class="_ _1"> </span>to<span class="_ _1"> </span>symbols<span class="_ _a"> </span>i<span class="_ _16"></span>s<span class="_ _a"> </span>based<span class="_ _1"> </span>on<span class="_ _1"> </span>neither<span class="_ _a"> </span>a<span class="_ _1"> </span>typical<span class="_ _1"> </span>binary<span class="_ _1"> </span>nor<span class="_ _a"> </span>a<span class="_ _1"> </span>gray-</div><div class="t m0 x1 h4 yb8 ff2 fs2 fc1 sc0 ls1 ws0">coded<span class="_ _6"> </span>method.<span class="_ _5"> </span>Rather<span class="_ _3"></span>,<span class="_ _6"> </span>the<span class="_ _5"> </span>L<span class="_ _2"></span>TE<span class="_ _5"> </span>specication<span class="_ _6"> </span>denes<span class="_ _5"> </span>a<span class="_ _6"> </span>custom<span class="_ _5"> </span>constellation<span class="_ _5"> </span>mapping.<span class="_ _6"> </span>L<span class="_ _2"></span>TE<span class="_ _5"> </span>also</div><div class="t m0 x1 h4 yb9 ff2 fs2 fc1 sc0 ls1 ws0">denes<span class="_ _5"> </span>modulation<span class="_ _6"> </span>symbols<span class="_ _5"> </span>in<span class="_ _5"> </span>such<span class="_ _5"> </span>a<span class="_ _6"> </span>way<span class="_ _5"> </span>that<span class="_ _5"> </span>the<span class="_ _6"> </span>average<span class="_ _6"> </span>signal<span class="_ _5"> </span>po<span class="_ _3"></span>wer<span class="_ _5"> </span>is<span class="_ _6"> </span>normalized<span class="_ _5"> </span>to<span class="_ _5"> </span>unity<span class="_ _b"></span>.</div><div class="t m0 x1 h7 yba ff3 fs5 fc1 sc0 ls0 ws0">4.1.1<span class="_ _d"> </span>MA<span class="_ _b"></span>TLAB<span class="_ _4"> </span>Examples</div><div class="t m0 x1 h4 ybb ff2 fs2 fc1 sc0 ls2 ws0">As<span class="_ _a"> </span>the<span class="_ _1"> </span>rst<span class="_ _1"> </span>step<span class="_ _1"> </span>in<span class="_ _1"> </span>modeling<span class="_ _a"> </span>the<span class="_ _1"> </span>L<span class="_ _2"></span>TE<span class="_ _1"> </span>downlink<span class="_ _a"> </span>processing<span class="_ _1"> </span>chain,<span class="_ _a"> </span>we<span class="_ _1"> </span>start<span class="_ _1"> </span>with<span class="_ _1"> </span>the<span class="_ _1"> </span>L<span class="_ _2"></span>TE<span class="_ _a"> </span>mod-</div><div class="t m0 x1 h4 ybc ff2 fs2 fc1 sc0 ls1 ws0">ulation<span class="_ _a"> </span>schemes.<span class="_ _a"> </span>The<span class="_ _a"> </span>following<span class="_ _5"> </span>two<span class="_ _a"> </span>MA<span class="_ _2"></span>TLAB<span class="_ _5"> </span>functions<span class="_ _a"> </span>show<span class="_ _5"> </span>how<span class="_ _5"> </span>you<span class="_ _a"> </span>can<span class="_ _a"> </span>easily<span class="_ _a"> </span>implement</div><div class="t m0 x1 h4 ybd ff2 fs2 fc1 sc0 ls2 ws0">the<span class="_ _1"> </span>L<span class="_ _2"></span>TE<span class="_ _a"> </span>modulation<span class="_ _1"> </span>and<span class="_ _1"> </span>demodulation<span class="_ _4"> </span>algorithms,<span class="_ _a"> </span>with<span class="_ _1"> </span>all<span class="_ _1"> </span>their<span class="_ _1"> </span>specications,<span class="_ _1"> </span>using<span class="_ _1"> </span>System</div><div class="t m0 x1 h4 ybe ff2 fs2 fc1 sc0 ls1 ws0">objects<span class="_ _a"> </span>of<span class="_ _1"> </span>the<span class="_ _1"> </span>Communications<span class="_ _1"> </span>System<span class="_ _1"> </span>T<span class="_ _2"></span>oolbox.</div></div><div class="pi" data-data='{"ctm":[1.961964,0.000000,0.000000,1.961964,0.000000,0.000000]}'></div></div>

<div id="pf4" class="pf w0 h0" data-page-no="4"><div class="pc pc4 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/626ce4b81fd0a5795280596b/bg4.jpg"><div class="t m0 x6 h6 y21 ff1 fs4 fc0 sc0 ls0 ws0">74<span class="_ _c"> </span><span class="ff2 ls5">Understanding<span class="_ _a"> </span>L<span class="_ _2"></span>TE<span class="_ _a"> </span>with<span class="_ _a"> </span>MA<span class="_ _2"></span>TLAB</span></div><div class="t m0 x7 h6 y22 ff2 fs4 fc0 sc0 ls0 ws0">®</div><div class="t m0 x49 he ybf ff1 fs9 fc0 sc0 ls0 ws0">Algorithm</div><div class="t m0 x49 h4 yc0 ff1 fs2 fc0 sc0 ls1 ws0">MA<span class="_ _2"></span>TLAB<span class="_ _a"> </span>function</div><div class="t m0 x49 hf yc1 ff4 fsa fc3 sc0 ls0 ws0">function<span class="_"> </span><span class="fc0 ls8">y=Modulator(u,<span class="_"> </span>Mode)</span></div><div class="t m0 x49 hf yc2 ff4 fsa fc4 sc0 ls0 ws0">%%<span class="_"> </span>Initialization</div><div class="t m0 x49 hf yc3 ff4 fsa fc3 sc0 ls0 ws0">persistent<span class="_"> </span><span class="fc0 ls9">QPSK<span class="_"> </span>Q<span class="ff8 ls0">A</span><span class="ls8">M16<span class="_"> </span>Q<span class="ff8 ls0">A</span>M64</span></span></div><div class="t m0 x49 hf yc4 ff4 fsa fc3 sc0 lsa ws0">if<span class="_"> </span><span class="fc0 lsb">isempty(QPSK)</span></div><div class="t m0 x2 hf yc5 ff4 fsa fc0 sc0 lsb ws0">QPSK<span class="_ _17"> </span>=<span class="_"> </span>comm.PSKModulator(4,<span class="_"> </span><span class="fc5 ls0">'BitInput',<span class="_"> </span>true,<span class="_"> </span><span class="fc3 ls8">...</span></span></div><div class="t m0 x4a hf yc6 ff4 fsa fc5 sc0 ls0 ws0">'PhaseOffset',<span class="_"> </span>pi/4,<span class="_"> </span>'SymbolMapping',<span class="_"> </span>'Custom',<span class="_"> </span><span class="fc3 ls8">...</span></div><div class="t m0 x4b hf yc7 ff4 fsa fc5 sc0 ls0 ws0">'CustomSymbolMapping',<span class="_"> </span>[<span class="lsc">0231<span class="_ _18"></span>]<span class="_ _18"></span>)<span class="_ _18"></span>;</span></div><div class="t m0 x2 hf yc8 ff4 fsa fc0 sc0 ls0 ws0">Q<span class="ff8">A</span><span class="ls8">M16<span class="_ _19"> </span>=<span class="_"> </span>comm.RectangularQ</span><span class="ff8">A</span><span class="ls8">MModulator(16,<span class="_"> </span></span><span class="fc5">'BitInput',true,<span class="fc3 ls8">...</span></span></div><div class="t m0 x9 hf yc9 ff4 fsa fc5 sc0 ls0 ws0">'NormalizationMethod','<span class="ff8">A</span>verage<span class="_"> </span>power',</div><div class="t m0 x4c hf yca ff4 fsa fc5 sc0 ls0 ws0">'SymbolMapping',<span class="_"> </span>'Custom',<span class="_"> </span><span class="fc3">...</span></div><div class="t m0 x4c hf ycb ff4 fsa fc5 sc0 ls0 ws0">'CustomSymbolMapping',</div><div class="t m0 x4c hf ycc ff4 fsa fc0 sc0 lsd ws0">[<span class="_ _18"></span>1<span class="_ _18"></span>11<span class="_ _18"></span>01<span class="_ _18"></span>41<span class="_ _18"></span>5981<span class="_ _18"></span>21<span class="_ _18"></span>310453267<span class="_ _18"></span>]<span class="_ _18"></span>)<span class="_ _18"></span>;</div><div class="t m0 x2 hf ycd ff4 fsa fc0 sc0 ls0 ws0">Q<span class="ff8">A</span><span class="ls8">M64<span class="_ _19"> </span>=<span class="_"> </span>comm.RectangularQ</span><span class="ff8">A</span><span class="ls8">MModulator(64,<span class="_"> </span></span><span class="fc5">'BitInput',true,<span class="fc3 ls8">...</span></span></div><div class="t m0 x9 hf yce ff4 fsa fc5 sc0 ls0 ws0">'NormalizationMethod','<span class="ff8">A</span>verage<span class="_"> </span>power',</div><div class="t m0 x9 hf ycf ff4 fsa fc5 sc0 ls0 ws0">'SymbolMapping',<span class="_"> </span>'Custom',</div><div class="t m0 x4c hf yd0 ff4 fsa fc5 sc0 ls0 ws0">'CustomSymbolMapping',</div><div class="t m0 x4c hf yd1 ff4 fsa fc0 sc0 lse ws0">[<span class="_ _18"></span>4<span class="_ _18"></span>74<span class="_ _18"></span>64<span class="_ _18"></span>24<span class="_ _18"></span>35<span class="_ _18"></span>95<span class="_ _18"></span>86<span class="_ _18"></span>26<span class="_ _18"></span>34<span class="_ _18"></span>54<span class="_ _18"></span>44<span class="_ _18"></span>04<span class="_ _18"></span>1<span class="fc3 ls0">...</span></div><div class="t m0 x4c hf yd2 ff4 fsa fc0 sc0 ls8 ws0">57<span class="_"> </span>56<span class="_"> </span>60<span class="_"> </span>61<span class="_"> </span>37<span class="_"> </span>36<span class="_"> </span>32<span class="_"> </span>33<span class="_"> </span>49<span class="_"> </span>48<span class="_"> </span>52<span class="_"> </span>53<span class="_"> </span>39</div><div class="t m0 x4c hf yd3 ff4 fsa fc0 sc0 lse ws0">3<span class="_ _18"></span>8<span class="_ _a"> </span>3<span class="_ _18"></span>43<span class="_ _18"></span>55<span class="_ _18"></span>15<span class="_ _18"></span>05<span class="_ _18"></span>45<span class="_ _18"></span>576231<span class="_ _18"></span>91<span class="_ _18"></span>82<span class="_ _18"></span>22<span class="_ _18"></span>35</div><div class="t m0 x4c hf yd4 ff4 fsa fc0 sc0 lse ws0">4011<span class="_ _18"></span>71<span class="_ _18"></span>62<span class="_ _18"></span>02<span class="_ _18"></span>11<span class="_ _18"></span>31<span class="_ _18"></span>2892<span class="_ _18"></span>52<span class="_ _18"></span>42<span class="_ _18"></span>82<span class="_ _18"></span>91<span class="_ _18"></span>5</div><div class="t m0 x4c hf yd5 ff4 fsa fc0 sc0 ls8 ws0">14<span class="_"> </span>10<span class="_"> </span>11<span class="_"> </span>27<span class="_"> </span>26<span class="_"> </span>30<span class="_"> </span>31]);</div><div class="t m0 x49 hf yd6 ff4 fsa fc3 sc0 ls8 ws0">end</div><div class="t m0 x49 hf yd7 ff4 fsa fc4 sc0 ls8 ws0">%%<span class="_"> </span>Processing</div><div class="t m0 x49 hf yd8 ff4 fsa fc3 sc0 lsf ws0">switch<span class="_"> </span><span class="fc0 ls8">Mode</span></div><div class="t m0 x2 hf yd9 ff4 fsa fc3 sc0 lsf ws0">case<span class="_"> </span>1</div><div class="t m0 x4d hf yda ff4 fsa fc0 sc0 lsb ws0">y=step(QPSK,<span class="_"> </span>u);</div><div class="t m0 x2 hf ydb ff4 fsa fc3 sc0 lsf ws0">case<span class="_"> </span>2</div><div class="t m0 x4d hf ydc ff4 fsa fc0 sc0 ls8 ws0">y=step(Q<span class="ff8 ls0">A</span>M16,<span class="_"> </span>u);</div><div class="t m0 x2 hf ydd ff4 fsa fc3 sc0 lsf ws0">case<span class="_"> </span>3</div><div class="t m0 x4d hf yde ff4 fsa fc0 sc0 ls8 ws0">y=step(Q<span class="ff8 ls0">A</span>M64,<span class="_"> </span>u);</div><div class="t m0 x49 hf ydf ff4 fsa fc3 sc0 ls8 ws0">end</div><div class="t m0 x1 h4 ye0 ff2 fs2 fc1 sc0 ls1 ws0">The<span class="_ _4"> </span>Modulator<span class="_ _1"> </span>function<span class="_ _4"> </span>has<span class="_ _1"> </span>two<span class="_ _4"> </span>input<span class="_ _1"> </span>arguments:<span class="_ _4"> </span>the<span class="_ _1"> </span>input<span class="_ _4"> </span>bit<span class="_ _1"> </span>stream<span class="_ _4"> </span>(<span class="ff3 ls0">u</span><span class="ls10">)<span class="_ _4"> </span>and<span class="_ _1"> </span>a<span class="_ _4"> </span>parameter</span></div><div class="t m0 x6 h4 ye1 ff2 fs2 fc1 sc0 ls1 ws0">representing<span class="_ _5"> </span>the<span class="_ _6"> </span>modulation<span class="_ _5"> </span>mode<span class="_ _5"> </span>(<span class="ff3 ls10">Mode</span>).<span class="_ _5"> </span>As<span class="_ _5"> </span>its<span class="_ _5"> </span>output,<span class="_ _6"> </span>the<span class="_ _5"> </span>function<span class="_ _5"> </span>computes<span class="_ _5"> </span>the<span class="_ _5"> </span>modulated</div><div class="t m0 x6 h4 ye2 ff2 fs2 fc1 sc0 ls1 ws0">symbols.<span class="_ _9"> </span>The<span class="_ _9"> </span>function<span class="_ _8"> </span>implements<span class="_ _9"> </span>the<span class="_ _9"> </span>three<span class="_ _9"> </span>different<span class="_ _8"> </span>types<span class="_ _9"> </span>of<span class="_ _9"> </span>modulator<span class="_ _9"> </span>used<span class="_ _9"> </span>in<span class="_ _9"> </span>the<span class="_ _8"> </span>L<span class="_ _2"></span>TE</div><div class="t m0 x6 h4 ye3 ff2 fs2 fc1 sc0 ls2 ws0">standard.<span class="_ _4"> </span>For<span class="_ _4"> </span>example,<span class="_ _4"> </span>in<span class="_ _8"> </span>the<span class="_ _4"> </span>case<span class="_ _8"> </span>of<span class="_ _4"> </span>QPSK,<span class="_ _8"> </span>we<span class="_ _4"> </span>use<span class="_ _4"> </span><span class="ff3 ls1">a<span class="_ _8"> </span>comm.PSKModulator<span class="_ _4"> </span><span class="ff2">System<span class="_ _8"> </span>object</span></span></div><div class="t m0 x6 h4 ye4 ff2 fs2 fc1 sc0 ls2 ws0">and<span class="_ _4"> </span>set<span class="_ _4"> </span>its<span class="_ _4"> </span>modulation<span class="_ _4"> </span>order<span class="_ _8"> </span>to<span class="_ _4"> </span>4.<span class="_ _4"> </span>Similarly<span class="_ _b"></span>,<span class="_ _4"> </span>in<span class="_ _4"> </span>the<span class="_ _4"> </span>case<span class="_ _4"> </span>of<span class="_ _8"> </span>16QAM<span class="_ _4"> </span>and<span class="_ _4"> </span>64QAM<span class="_ _4"> </span>we<span class="_ _4"> </span>use<span class="_ _4"> </span>the</div><div class="t m0 x6 h4 ye5 ff3 fs2 fc1 sc0 ls1 ws0">comm.RectangulatQAMModulator<span class="_ _4"> </span><span class="ff2">System<span class="_ _1"> </span>objects<span class="_ _4"> </span>and<span class="_ _4"> </span>set<span class="_ _1"> </span>their<span class="_ _4"> </span>modulation<span class="_ _4"> </span>orders<span class="_ _1"> </span>to<span class="_ _4"> </span>16<span class="_ _4"> </span>and</span></div><div class="t m0 x6 h4 ye6 ff2 fs2 fc1 sc0 ls1 ws0">64,<span class="_ _a"> </span>respectiv<span class="_ _b"></span>ely<span class="_ _b"></span>.<span class="_ _a"> </span>Depending<span class="_ _1"> </span>on<span class="_ _a"> </span>the<span class="_ _a"> </span>value<span class="_ _5"> </span>of<span class="_ _a"> </span>the<span class="_ _a"> </span>modulation<span class="_ _a"> </span>mode,<span class="_ _1"> </span>we<span class="_ _a"> </span>process<span class="_ _a"> </span>the<span class="_ _a"> </span>input<span class="_ _a"> </span>bits<span class="_ _a"> </span>to</div><div class="t m0 x6 h4 ye7 ff2 fs2 fc1 sc0 ls1 ws0">generate<span class="_ _a"> </span>the<span class="_ _1"> </span>modulated<span class="_ _1"> </span>symbols<span class="_ _1"> </span>as<span class="_ _1"> </span>the<span class="_ _1"> </span>output.</div><div class="t m0 x1 h4 ye8 ff2 fs2 fc1 sc0 ls1 ws0">T<span class="_ _2"></span>o<span class="_ _4"> </span>ensure<span class="_ _1"> </span>that<span class="_ _4"> </span>the<span class="_ _4"> </span>System<span class="_ _1"> </span>object<span class="_ _4"> </span>exactly<span class="_ _1"> </span>matches<span class="_ _4"> </span>what<span class="_ _4"> </span>the<span class="_ _1"> </span>L<span class="_ _2"></span>TE<span class="_ _4"> </span>standard<span class="_ _4"> </span>species,<span class="_ _1"> </span>we<span class="_ _4"> </span>can</div><div class="t m0 x6 h4 ye9 ff2 fs2 fc1 sc0 ls2 ws0">set<span class="_ _a"> </span>other<span class="_ _1"> </span>properties:</div></div><div class="pi" data-data='{"ctm":[1.961964,0.000000,0.000000,1.961964,0.000000,0.000000]}'></div></div>

<div id="pf5" class="pf w0 h0" data-page-no="5"><div class="pc pc5 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/626ce4b81fd0a5795280596b/bg5.jpg"><div class="t m0 x1 h6 y5c ff2 fs4 fc0 sc0 ls5 ws0">Modulation<span class="_ _a"> </span>and<span class="_ _a"> </span>Coding<span class="_ _14"> </span><span class="ff1 ls0">75</span></div><div class="t m0 x1 h10 yea ff2 fs2 fc0 sc0 ls11 ws0">1.<span class="_"> </span><span class="fc1 ls1">W<span class="_ _2"></span>e<span class="_ _a"> </span>can<span class="_ _5"> </span>set<span class="_ _a"> </span>BitInput<span class="_ _6"> </span><span class="ff6 ls0">=<span class="_ _6"> </span></span>true.<span class="_ _5"> </span>This<span class="_ _a"> </span>means<span class="_ _a"> </span>that<span class="_ _5"> </span>the<span class="_ _a"> </span>modulator<span class="_ _5"> </span>inputs<span class="_ _a"> </span>are<span class="_ _a"> </span>interpreted<span class="_ _5"> </span>as<span class="_ _a"> </span>a<span class="_ _5"> </span>vector</span></div><div class="t m0 x4e h4 yeb ff2 fs2 fc1 sc0 ls1 ws0">of<span class="_ _1"> </span>bit<span class="_ _1"> </span>values.<span class="_ _1"> </span>For<span class="_ _1"> </span>example,<span class="_ _a"> </span>in<span class="_ _4"> </span>case<span class="_ _a"> </span>of<span class="_ _4"> </span>a<span class="_ _a"> </span>QPSK<span class="_ _4"> </span>modulator<span class="_ _a"> </span>since<span class="_ _4"> </span>e<span class="_ _b"></span>very<span class="_ _1"> </span>2<span class="_ _1"> </span>bits<span class="_ _4"> </span>are<span class="_ _a"> </span>mapped<span class="_ _4"> </span>to</div><div class="t m0 x4e h4 yec ff2 fs2 fc1 sc0 ls1 ws0">one<span class="_ _a"> </span>modulation<span class="_ _1"> </span>symbol,<span class="_ _1"> </span>the<span class="_ _1"> </span>size<span class="_ _1"> </span>of<span class="_ _1"> </span>the<span class="_ _a"> </span>output<span class="_ _1"> </span>vector<span class="_ _1"> </span>is<span class="_ _a"> </span>half<span class="_ _1"> </span>that<span class="_ _1"> </span>of<span class="_ _1"> </span>the<span class="_ _1"> </span>input<span class="_ _a"> </span>vector<span class="_ _b"></span>.</div><div class="t m0 x1 h10 yed ff2 fs2 fc0 sc0 ls11 ws0">2.<span class="_"> </span><span class="fc1 ls1">W<span class="_ _2"></span>e<span class="_ _1"> </span>can<span class="_ _1"> </span>set<span class="_ _1"> </span>PhaseOffset<span class="_ _6"> </span><span class="ff6 ls0">=<span class="_ _1a"> </span></span>pi/4.<span class="_ _a"> </span>This<span class="_ _1"> </span>means<span class="_ _1"> </span>that<span class="_ _1"> </span>the<span class="_ _1"> </span>modulated<span class="_ _1"> </span>symbols<span class="_ _1"> </span>correspond<span class="_ _1"> </span>to<span class="_ _a"> </span>four</span></div><div class="t m0 x4e h4 yee ff2 fs2 fc1 sc0 ls1 ws0">points<span class="_ _5"> </span>in<span class="_ _a"> </span>the<span class="_ _a"> </span>complex<span class="_ _a"> </span>plane<span class="_ _a"> </span>with<span class="_ _a"> </span>unity<span class="_ _a"> </span>length,<span class="_ _a"> </span>whose<span class="_ _a"> </span>angles<span class="_ _a"> </span>are<span class="_ _a"> </span>chosen<span class="_ _a"> </span>from<span class="_ _a"> </span>the<span class="_ _a"> </span>following</div><div class="t m0 x4e h10 yef ff2 fs2 fc1 sc0 ls12 ws0">set:<span class="_ _a"> </span>[3<span class="ff9 ls0">𝜋<span class="_ _1b"> </span></span><span class="ls2">/4,<span class="_ _a"> </span><span class="ff9 ls0">𝜋<span class="_ _1b"> </span></span>/4,<span class="_ _a"> </span><span class="ff6 ls0">−<span class="ff9">𝜋<span class="_ _1b"> </span></span></span>/4,<span class="_ _1"> </span><span class="ff6 ls0">−<span class="ff2">3<span class="ff9">𝜋<span class="_ _16"></span></span></span></span></span>/4].</div><div class="t m0 x1 h4 yf0 ff2 fs2 fc0 sc0 ls11 ws0">3.<span class="_"> </span><span class="fc1 ls1">Using<span class="_ _4"> </span>the<span class="_ _4"> </span>CustomSymbolMapping<span class="_ _4"> </span>property<span class="_ _2"></span>,<span class="_ _4"> </span>we<span class="_ _4"> </span>can<span class="_ _4"> </span>ensure<span class="_ _4"> </span>that<span class="_ _4"> </span>the<span class="_ _4"> </span>bit<span class="_ _4"> </span>patterns<span class="_ _4"> </span>specied</span></div><div class="t m0 x4e h4 yf1 ff2 fs2 fc1 sc0 ls2 ws0">in<span class="_ _a"> </span>L<span class="_ _2"></span>TE<span class="_ _1"> </span>result<span class="_ _1"> </span>in<span class="_ _1"> </span>corresponding<span class="_ _1"> </span>output<span class="_ _1"> </span>symbols.</div><div class="t m0 x2 h4 yf2 ff2 fs2 fc1 sc0 ls1 ws0">Note<span class="_ _4"> </span>that<span class="_ _4"> </span>the<span class="_ _4"> </span>L<span class="_ _2"></span>TE,<span class="_ _1"> </span>like<span class="_ _4"> </span>other<span class="_ _4"> </span>mobile<span class="_ _4"> </span>standards,<span class="_ _4"> </span>does<span class="_ _4"> </span>not<span class="_ _1"> </span>make<span class="_ _4"> </span>any<span class="_ _4"> </span>recommendations<span class="_ _4"> </span>con-</div><div class="t m0 x1 h4 yf3 ff2 fs2 fc1 sc0 ls1 ws0">cerning<span class="_ _8"> </span>the<span class="_ _8"> </span>operations<span class="_ _8"> </span>performed<span class="_ _8"> </span>in<span class="_ _8"> </span>the<span class="_ _8"> </span>recei<span class="_ _b"></span>ver<span class="_ _b"></span>.<span class="_ _8"> </span>Hence,<span class="_ _8"> </span>all<span class="_ _8"> </span>the<span class="_ _8"> </span>receiv<span class="_ _3"></span>er<span class="_ _8"> </span>specications<span class="_ _8"> </span>pre-</div><div class="t m0 x1 h4 yf4 ff2 fs2 fc1 sc0 ls1 ws0">sented<span class="_ _4"> </span>in<span class="_ _4"> </span>this<span class="_ _1"> </span>book<span class="_ _4"> </span>can<span class="_ _4"> </span>be<span class="_ _4"> </span>considered<span class="_ _4"> </span>typical<span class="_ _4"> </span>“in<span class="_ _b"></span>verse”<span class="_ _4"> </span>operations<span class="_ _4"> </span>of<span class="_ _1"> </span>operations<span class="_ _4"> </span>specied<span class="_ _4"> </span>in</div><div class="t m0 x1 h4 yf5 ff2 fs2 fc1 sc0 ls2 ws0">the<span class="_ _4"> </span>transmitter<span class="_ _b"></span>.<span class="_ _8"> </span>These<span class="_ _8"> </span>proposed<span class="_ _4"> </span>in<span class="_ _3"></span>verse<span class="_ _4"> </span>operations<span class="_ _4"> </span>represent<span class="_ _8"> </span>best<span class="_ _8"> </span>ef<span class="_ _3"></span>forts<span class="_ _4"> </span>to<span class="_ _8"> </span>recov<span class="_ _b"></span>er<span class="_ _8"> </span>the<span class="_ _8"> </span>esti-</div><div class="t m0 x1 h4 yf6 ff2 fs2 fc1 sc0 ls2 ws0">mate<span class="_ _1"> </span>of<span class="_ _1"> </span>the<span class="_ _1"> </span>transmitted<span class="_ _4"> </span>bits.<span class="_ _a"> </span>Although<span class="_ _1"> </span>not<span class="_ _4"> </span>specied<span class="_ _a"> </span>in<span class="_ _1"> </span>the<span class="_ _4"> </span>standard,<span class="_ _a"> </span>it<span class="_ _1"> </span>is<span class="_ _4"> </span>necessary<span class="_ _a"> </span>to<span class="_ _1"> </span>include</div><div class="t m0 x1 h4 yf7 ff2 fs2 fc1 sc0 ls1 ws0">these<span class="_ _5"> </span>receiv<span class="_ _3"></span>er-side<span class="_ _5"> </span>in<span class="_ _b"></span>verse<span class="_ _5"> </span>operations<span class="_ _a"> </span>in<span class="_ _5"> </span>order<span class="_ _5"> </span>to<span class="_ _a"> </span>ev<span class="_ _b"></span>aluate<span class="_ _5"> </span>t<span class="_ _16"></span>he<span class="_ _5"> </span>accuracy<span class="_ _5"> </span>and<span class="_ _5"> </span>performance<span class="_ _a"> </span>of<span class="_ _5"> </span>the</div><div class="t m0 x1 h4 yf8 ff2 fs2 fc1 sc0 ls0 ws0">system.</div><div class="t m0 x2 h4 yf9 ff2 fs2 fc1 sc0 ls1 ws0">As<span class="_ _9"> </span>demodulation<span class="_ _f"> </span>is<span class="_ _f"> </span>the<span class="_ _9"> </span>inv<span class="_ _b"></span>erse<span class="_ _f"> </span>operation<span class="_ _f"> </span>for<span class="_ _9"> </span>modulation,<span class="_ _f"> </span>we<span class="_ _9"> </span>now<span class="_ _9"> </span>present<span class="_ _f"> </span>some<span class="_ _f"> </span>typical</div><div class="t m0 x1 h4 yfa ff2 fs2 fc1 sc0 ls1 ws0">approaches<span class="_ _8"> </span>to<span class="_ _8"> </span>demodulation.<span class="_ _9"> </span>In<span class="_ _8"> </span>the<span class="_ _8"> </span>Demodulator<span class="_ _9"> </span>function,<span class="_ _8"> </span>we<span class="_ _8"> </span>use<span class="_ _8"> </span>the<span class="_ _9"> </span>same<span class="_ _8"> </span>three<span class="_ _8"> </span>modula-</div><div class="t m0 x1 h4 yfb ff2 fs2 fc1 sc0 ls1 ws0">tion<span class="_ _5"> </span>types<span class="_ _a"> </span>used<span class="_ _a"> </span>in<span class="_ _5"> </span>L<span class="_ _2"></span>TE,<span class="_ _a"> </span>and<span class="_ _a"> </span>depending<span class="_ _5"> </span>on<span class="_ _a"> </span>the<span class="_ _a"> </span>modulation<span class="_ _5"> </span>mode,<span class="_ _a"> </span>we<span class="_ _a"> </span>process<span class="_ _5"> </span>the<span class="_ _a"> </span>input<span class="_ _a"> </span>symbols</div><div class="t m0 x1 h4 yfc ff2 fs2 fc1 sc0 ls1 ws0">to<span class="_ _5"> </span>generate<span class="_ _6"> </span>the<span class="_ _5"> </span>demodulated<span class="_ _5"> </span>output.<span class="_ _5"> </span>As<span class="_ _5"> </span>discussed<span class="_ _5"> </span>in<span class="_ _6"> </span>the<span class="_ _5"> </span>previous<span class="_ _6"> </span>section,<span class="_ _5"> </span>demodulation<span class="_ _5"> </span>can<span class="_ _5"> </span>be</div><div class="t m0 x1 h4 yfd ff2 fs2 fc1 sc0 ls1 ws0">based<span class="_ _a"> </span>on<span class="_ _1"> </span>either<span class="_ _a"> </span>hard-decision<span class="_ _1"> </span>decoding<span class="_ _a"> </span>or<span class="_ _1"> </span>soft-decision<span class="_ _1"> </span>decoding.<span class="_ _a"> </span>In<span class="_ _1"> </span>hard-decision<span class="_ _a"> </span>decoding,</div><div class="t m0 x1 h4 yfe ff2 fs2 fc1 sc0 ls2 ws0">the<span class="_ _8"> </span>input<span class="_ _8"> </span>symbols<span class="_ _8"> </span>of<span class="_ _8"> </span>a<span class="_ _4"> </span>demodulator<span class="_ _8"> </span>are<span class="_ _8"> </span>mapped<span class="_ _8"> </span>to<span class="_ _8"> </span>estimated<span class="_ _8"> </span>bits,<span class="_ _8"> </span>whereas<span class="_ _8"> </span>in<span class="_ _8"> </span>soft-decision</div><div class="t m0 x1 h4 yff ff2 fs2 fc1 sc0 ls1 ws0">decoding<span class="_ _a"> </span>the<span class="_ _1"> </span>output<span class="_ _1"> </span>is<span class="_ _1"> </span>a<span class="_ _1"> </span>vector<span class="_ _a"> </span>of<span class="_ _1"> </span>log-likelihood<span class="_ _a"> </span>ratios<span class="_ _1"> </span>(LLRs).</div><div class="t m0 x2 h4 y100 ff2 fs2 fc1 sc0 ls1 ws0">The<span class="_ _e"> </span>function<span class="_ _e"> </span><span class="ff3 ls2">DemodulatorHar<span class="_ _b"></span>d.m<span class="_ _e"> </span><span class="ff2 ls1">shows<span class="_ _e"> </span>a<span class="_ _e"> </span>demodulation<span class="_ _e"> </span>implementation<span class="_ _e"> </span>that<span class="_ _e"> </span>employs</span></span></div><div class="t m0 x1 h4 y101 ff2 fs2 fc1 sc0 ls1 ws0">hard-decision<span class="_ _a"> </span>decoding.<span class="_ _1"> </span>The<span class="_ _a"> </span>function<span class="_ _1"> </span>takes<span class="_ _a"> </span>as<span class="_ _a"> </span>inputs<span class="_ _1"> </span>the<span class="_ _a"> </span>received<span class="_ _5"> </span>modulated<span class="_ _1"> </span>symbols<span class="_ _a"> </span>(<span class="ff3 ls0">u</span><span class="ls11">)<span class="_ _1"> </span>and</span></div><div class="t m0 x1 h4 y102 ff2 fs2 fc1 sc0 ls1 ws0">the<span class="_ _a"> </span>modulation<span class="_ _1"> </span>mode<span class="_ _1"> </span>(<span class="ff3 ls10">Mode</span>).<span class="_ _1"> </span>The<span class="_ _1"> </span>function<span class="_ _1"> </span>output<span class="_ _a"> </span>comprises<span class="_ _1"> </span>the<span class="_ _1"> </span>demodulated<span class="_ _1"> </span>bits.</div><div class="t m0 x1a he y103 ff1 fs9 fc0 sc0 ls0 ws0">Algorithm</div><div class="t m0 x1a h4 y104 ff1 fs2 fc0 sc0 ls1 ws0">MA<span class="_ _2"></span>TLAB<span class="_ _a"> </span>function</div><div class="t m0 x1a hf y105 ff4 fsa fc3 sc0 ls0 ws0">function<span class="_"> </span><span class="fc0 ls8">y=DemodulatorHard(u,<span class="_"> </span>Mode)</span></div><div class="t m0 x1a hf y106 ff4 fsa fc4 sc0 ls0 ws0">%%<span class="_"> </span>Initialization</div><div class="t m0 x1a hf y107 ff4 fsa fc3 sc0 ls8 ws0">persistent<span class="_"> </span><span class="fc0 ls9">QPSK<span class="_"> </span>Q<span class="ff8 ls0">A</span><span class="ls8">M16<span class="_"> </span>Q<span class="ff8 ls0">A</span>M64</span></span></div><div class="t m0 x1a hf y108 ff4 fsa fc3 sc0 lsa ws0">if<span class="_"> </span><span class="fc0 lsb">isempty(QPSK)</span></div><div class="t m0 x4f hf y109 ff4 fsa fc0 sc0 lsb ws0">QPSK<span class="_"> </span>=<span class="_"> </span>comm.PSKDemodulator(<span class="fc3 ls0">...</span></div><div class="t m0 x50 hf y10a ff4 fsa fc5 sc0 ls0 ws0">'ModulationOrder',<span class="_"> </span>4,<span class="_"> </span><span class="fc3">...</span></div><div class="t m0 x50 hf y10b ff4 fsa fc5 sc0 ls0 ws0">'BitOutput',<span class="_"> </span>true,<span class="_"> </span><span class="fc3">...</span></div><div class="t m0 x50 hf y10c ff4 fsa fc5 sc0 ls0 ws0">'PhaseOffset',<span class="_"> </span>pi/4,<span class="_"> </span>'SymbolMapping',<span class="_"> </span>'Custom',<span class="_"> </span><span class="fc3 ls8">...</span></div><div class="t m0 x50 hf y10d ff4 fsa fc5 sc0 ls0 ws0">'CustomSymbolMapping',<span class="_"> </span>[0<span class="_"> </span>2<span class="_"> </span>3<span class="_"> </span>1]);</div><div class="t m0 x4f hf y10e ff4 fsa fc0 sc0 ls0 ws0">Q<span class="ff8">A</span><span class="ls8">M16<span class="_"> </span>=<span class="_"> </span>comm.RectangularQ</span><span class="ff8">A</span><span class="ls8">MDemodulator(<span class="fc3">...</span></span></div><div class="t m0 x50 hf y10f ff4 fsa fc5 sc0 ls0 ws0">'ModulationOrder',<span class="_"> </span>16,<span class="_ _1c"> </span><span class="fc3">...</span></div><div class="t m0 x50 hf y110 ff4 fsa fc5 sc0 ls0 ws0">'BitOutput',<span class="_"> </span>true,<span class="_"> </span><span class="fc3">...</span></div><div class="t m0 x50 hf y111 ff4 fsa fc5 sc0 ls0 ws0">'NormalizationMethod',<span class="_"> </span>'<span class="ff8">A</span>verage<span class="_"> </span>power',<span class="_"> </span>'SymbolMapping',<span class="_"> </span>'Custom',<span class="_"> </span><span class="fc3">...</span></div><div class="t m0 x50 hf y112 ff4 fsa fc5 sc0 ls0 ws0">'CustomSymbolMapping',<span class="_"> </span>[11<span class="_"> </span>10<span class="_"> </span>14<span class="_"> </span>1<span class="lsd">5981<span class="_ _18"></span>21<span class="_ _18"></span>310453267<span class="_ _18"></span>]<span class="_ _18"></span>)<span class="_ _18"></span>;</span></div></div><div class="pi" data-data='{"ctm":[1.961964,0.000000,0.000000,1.961964,0.000000,0.000000]}'></div></div>