OFDM MATLAB 仿真程序.doc

6t1F6WGdH5F ur.O,mB0X i1k,x0Y+R$U5U5? *x0echo off;clear all;close all;clc;1fKf&|r0gU-D-_0fprintf( OFDM仿真n) ;wXXin%m,ZB0tic% - %B6)eu Zx0% 参数定义 %3TNZk9x)OI6xK0% - %中国通信网无限分享w/DDoK% Initialize the parameterskH#Bs4J o0NumLoop = 1000;中国通信网无限分享8C.e/AUyfNumSubc = 128;pK1dA?;O0NumCP = 8;k+y$E X&y6RW0SyncDelay = 0;中国通信网无限分享0d*m;*|.J/aC#i(X0% 子载波数 128!hb%j!MTuO;Y2V0h0% 位数/ 符号 2中国通信网无限分享$k6,N?% 符号数/ 载波 1000p;I3sOzRR0% 训练符号数 0中国通信网无限分享8S3V_!Deej% 循环前缀长度 8 (1/16)*T+H7g/6O2d)pJ0H 0% 调制方式 4-QAMReH3H Cq$y9C0% 多径信道数 3 中国通信网无限分享(HF,N1u;xH% IFFT Size 128 中国通信网无限分享 !vu)fQ% 信道最大时延 2中国通信网无限分享%F-CW9 W|.I% - %:g?7&P$u3J-P(U1W0% QAM MODULATION %;r r asd6z|0% - %nS0KR2j0YSi|Md0% Generate the random binary stream for transmit testpk.j,FqU;z-y0BitsTx = floor(rand(1,NumLoop*NumSubc)*2);% Modulate (Generates QAM symbols)中国通信网无限分享tW6F0Wy/SK% input: BitsTx(1,NumLoop*NumSubc); output: SymQAM(NumLoop,NumSubc/2)中国通信网无限分享2w2x/eB4S2+SymQAMtmp = reshape(BitsTx,2,NumLoop*NumSubc/2).;fM8POZ) j0SymQAMtmptmp = bi2de(SymQAMtmp,2,left-msb);*YK.F/et00%-Xic0% 函数说明：m4Dh*T cDG0% bin2dec(binarystr) interprets the binary string binarystr and returns the中国通信网无限分享GtZV8A% equivalent decimal number.FyS0pQTFRl0% bi2de是把列向量的每一个元素都由2进制变为10进制n|L &$?0%D = BI2DE(.,MSBFLAG) uses MSBFLAG to determine the input orientation.中国通信网无限分享v:z7YKIKU;r Mj_% MSBFLAG has two possible values, right-msb and left-msb. Giving ar4Uo5J0% right-msb MSBFLAG does not change the functions default behavior.中国通信网无限分享 _ f5bA&uAl%Giving a left-msb MSBFLAG flips the input orientation such that the中国通信网无限分享7an gOqp2W_8N% MSB is on the left.中国通信网无限分享X;3f %Z+E5z;g% % % D = BI2DE(.,P) converts a base P vector to a decimal value.中国通信网无限分享#h! H6G% % Examples:中国通信网无限分享4E#o62rY/n6Kqx+n,d% % B = 0 0 1 1; 1 0 1 0;中国通信网无限分享8j*Q eK5z% % T = 0 1 1; 2 1 0;WuxX C9q%s/b0yR2QY-R6D0% % D = bi2de(B) D = bi2de(B,left-msb) D = bi2de(T,3)FjQUJ*H0% % D = D = D =中国通信网无限分享!R)k i3jux yg% % 12 3 12中国通信网无限分享C |;yk f% % 5 10 5中国通信网无限分享H k B-g3b!R)gj%-% QAM modulation 中国通信网无限分享 F+? f2H+q4D% 00-1-i,01-1+i,10-1-i,11-1+i5e-dxA!I:w0% 利用查表法进行QAM星座映射GVa#W/9(UJy0QAMTable = -1-i -1+i 1-i 1+i;中国通信网无限分享:Y.j)ozh YSymQAM = QAMTable(SymQAMtmptmp+1);% - %L$T-X8_*nO!r C0% IFFT %中国通信网无限分享4M9$E#Cn% - %中国通信网无限分享hZT$vZ% input: SymQAM(NumLoop,NumSubc/2); output: SymIFFT(NumSubc,NumLoop)中国通信网无限分享+Ek/nj fR,B/ESymIFFT = zeros(NumSubc,NumLoop);:#h&P5r29W H&I8t% O0SymIFFTtmp = reshape(SymQAM,NumSubc/2,NumLoop);中国通信网无限分享wPO!v SymIFFTtmptmp = zeros(NumSubc,NumLoop);)A!_vb?F)Ci0SymIFFTtmptmp(1,:) = real(SymIFFTtmp(1,:); % 实数1Nmkgh0SymIFFTtmptmp(NumSubc/2+1,:) = imag(SymIFFTtmp(1,:); % 实数RX+FD0% 这么安排矩阵的目的是为了构造共轭对称矩阵中国通信网无限分享7q N m b2G!RC% 共轭对称矩阵的特点是 在ifft/fft的矢量上 N点的矢量/t qP6?,q3n#y+Q0% 在0，N/2点必须是实数 一般选为0中国通信网无限分享G3J4A*j.Jz+x-r4% 1至N/2点 与 （N/2）+1至N-1点关于N/2共轭对称SymIFFTtmptmp(2:NumSubc/2,:) = SymIFFTtmp(2:NumSubc/2,:);中国通信网无限分享CPqE7bSymIFFTtmptmp(NumSubc/2+2):NumSubc,:) = flipdim(conj(SymIFFTtmp(2:NumSubc/2,:),1);H_vE(O6G0%-Q6h,j/M#XP$Wv0% 函数说明：)sJE7P0% B = flipdim(A,dim) returns A with dimension dim flipped.中国通信网无限分享#o%i;My*Ug#b% When the value of dim is 1, the array is flipped row-wise down. When dim is 2,中国通信网无限分享+Agi w;H% the array is flipped columnwise left to right. flipdim(A,1) is the same asCGY;h%Ow+B0% flipud(A), and flipdim(A,2) is the same as fliplr(A).C4LeS0%-中国通信网无限分享BguRm% % a = 1 2 3; 4 5 6; 7 8 9; 10 11 128w*d9P,q%f0% % a =中国通信网无限分享4q 6KA4r(N S0% % 1 2 3中国通信网无限分享Ey;w;Se% % 4 5 6中国通信网无限分享)JT%F j R% % 7 8 9中国通信网无限分享0A2k nif)a,c% % 10 11 12h!W/M k(T0% % b = flipdim(a,1)YWW;V0u0% % b =CD:jfHs0% % 10 11 12中国通信网无限分享w)XzU,|,QhC*E% % 7 8 9*SI(f;Y*w Y0% % 4 5 6中国通信网无限分享s rWx7k% % 1 2 3SymIFFT = ifft(SymIFFTtmptmp,NumSubc,1);% - %)gB)N Rk*Lls0% Add cyclic prefix %中国通信网无限分享-k9r4Ia g p$HT&L% - %中国通信网无限分享:_1jkbI6eP9% input: SymIFFT(NumSubc,NumLoop); output: SymCP(NumSubc + NumCP,NumLoop)Y9JftM0NumAddPrefix = NumSubc + NumCP;中国通信网无限分享,nK3e,Z$g#b2lnSymCP = zeros(NumAddPrefix,NumLoop);gnB9bXu9p b*a0RowPrefix = (NumSubc - NumCP + 1):NumSubc;中国通信网无限分享V_W;9m1QNSymCP = SymIFFT(RowPrefix,:);SymIFFT;% - %ikG(Cp,_$v*db0% Go through the channel %0 ai0% - %0w!jv| gJ Q0% input: SymCP(NumSubc + NumCP,NumLoop); output: SymCh(1,(NumSubc + NumCP)*NumLoop)中国通信网无限分享D-Do5P0h1uSymCh = zeros(1,(NumSubc + NumCP)*NumLoop);中国通信网无限分享rSn0WSymChtmp = SymCP(:).; % 进行这个转置操作之后就成了一个矢量y5kU)c$k12|-r0% 相当于把矩阵的列向量依次排列 改变为一个行向量$m B&x$lw0Ch = 1 1/2 1/4;9a&u4XLI0I0SymChtmptmp = filter(Ch,1,SymChtmp);2+Q.O y |4N+ q0%-中国通信网无限分享t&z 7|I8?% 函数说明：中国通信网无限分享|0GXFW% Firlter data with an infinite impulse response (IIR) or finite impulse response1a5X ?R2P0% (FIR) filter中国通信网无限分享K4RGnez j c% y = filter(b,a,X) filters the data in vector X with the filter described by:v4Ef f!M a0% numerator coefficient vector b and denominator coefficient vector a. If a(1) is8H5z2n|0,Dj*v0% not equal to 1, filter normalizes the filter coefficients by a(1). If a(1) equals)A&W$Rb n8c0% 0, filter returns an error.中国通信网无限分享Q bxG3f8K%-中国通信网无限分享Q2Ao4IYX Z1eP*i% If X is a matrix, filter operates on the columns of X. If X is a multidimensional中国通信网无限分享OlAHJ% array, filter operates on the first nonsingleton dimension.L;P 8X r7u p0%-% Add the AWGNGd(S K0BerSnrTable = zeros(20,3);+a P#c$y0for snr=0:19; % = SNR + 10*log10(log2(2);6PJ81_Sej,x0yV)Y0 BerSnrTable(snr+1,1) = snr;-e2 u0n%qWM&|ka0SymCh = awgn(SymChtmptmp,snr,measured);zA,jj QiZ,j0%-中国通信网无限分享$PuGK3V c J% 函数说明：)N v;6Akp2kbL0% AWGN Add white Gaussian noise to a signal.#|l_;V;Z-Z5j0% Y = AWGN(X,SNR) adds white Gaussian noise to X. The SNR is in dB.5f;l KA:v0% The power of X is assumed to be 0 dBW. If X is complex, then ;6_G7d0% AWGN adds complex noise.中国通信网无限分享Mi$Y3Qr5PV% -:dX(Wa| a0% Y = AWGN(X,SNR,SIGPOWER) when SIGPOWER is numeric, it represents K2F.o kdP0% the signal power in dBW. When SIGPOWER is measured, AWGN measures中国通信网无限分享7iSft,uM+G% the signal power before adding noise.q7j sX0% -中国通信网无限分享g%LBg T g-k% Y = AWGN(X,SNR,SIGPOWER,STATE) resets the state of RANDN to STATE.中国通信网无限分享2jnH H !_% 中国通信网无限分享K.w cW;j% Y = AWGN(., POWERTYPE) specifies the units of SNR and SIGPOWER.VAvb*P0% POWERTYPE can be db or linear. If POWERTYPE is db, then SNR中国通信网无限分享 E4x4?% is measured in dB and SIGPOWER is measured in dBW. If POWERTYPE isNR&mqe0% linear, then SNR is measured as a ratio and SIGPOWER is measured中国通信网无限分享%s1m/VT.EZ% in Watts.中国通信网无限分享B,n:eBs% hxr?*u0% Example: To specify the power of X to be 0 dBW and add noise to produce中国通信网无限分享U&uI-a8KqF+V9M% an SNR of 10dB, use:W0m,:?A0% X = sqrt(2)*sin(0:pi/8:6*pi);U(l!r$Q-kj0% Y = AWGN(X,10,0);中国通信网无限分享JV+D(c9uJ4deh?% 中国通信网无限分享6(A;yMW wv% Example: To specify the power of X to be 0 dBW, set RANDN to the 1234th#A7V Fx0% state and add noise to produce an SNR of 10dB, use:中国通信网无限分享)k&cE?T-e% X = sqrt(2)*sin(0:pi/8:6*pi);中国通信网无限分享%w*R U3EPs5N% Y = AWGN(X,10,0,1234);LY4ZJ0% -A*ppgc0% Example: To specify the power of X to be 3 Watts and add noise to中国通信网无限分享P7lL0j$iP.j% produce a linear SNR of 4, use:中国通信网无限分享QE*xs1:x6IAa4aQ% X = sqrt(2)*sin(0:pi/8:6*pi);中国通信网无限分享bH H |3sA.g$Yt.D% Y = AWGN(X,4,3,linear);中国通信网无限分享 JB iB*t% D5P0Uk4g-P0% Example: To cause AWGN to measure the power of X, set RANDN to the 中国通信网无限分享JG?o#l|O#v% 1234th state and add noise to produce a linear SNR of 4, use:cy;T$?Jqb?0% X = sqrt(2)*sin(0:pi/8:6*pi);中国通信网无限分享)d9AFK1?!bZ,6Sa% Y = AWGN(X,4,measured,1234,linear);% - %3tn&e0% Remove Guard Intervals %中国通信网无限分享 CGP%O3C/ewa% - %:G6k)K8A)O*B.BA0% input: SymCh(1,(NumSubc + NumCP)*NumLoop); output: SymDeCP(NumSubc,NumLoop)中国通信网无限分享r5hw*scx%c5?SymDeCP = zeros(NumSubc,NumLoop);&EbZ TG H&ZD8rlYq:r0SymDeCPtmp = reshape(SymCh,NumSubc + NumCP,NumLoop);9pv:n!Z&gw#J40SymDeCP = SymDeCPtmp(NumCP+1+SyncDelay):NumAddPrefix+SyncDelay,:);% - %V3t5E0N$0% FFT %中国通信网无限分享m_.Ev Z9O,w/% - %CQ-f%|K1z(k1JJ0% input: SymDeCP(NumSubc,NumLoop); output: SymFFT(NumSubc,NumLoop)MfIqOE!Y0SymFFT = fft(SymDeCP,NumSubc,1);% - %中国通信网无限分享 m.B i9k*O%l% Make Decision(Include DeQAM) %$JY2P(vjz0% - %o7fI?HM z4_0% SymFFT(NumSubc,NumLoop); output: SymDec(NumSubc,NumLoop)中国通信网无限分享 ACt lm5D8SymDec = zeros(NumSubc,NumLoop);+mO5Vgm!A#b0SymEqtmp(1,:) = SymFFT(1,:)+i*SymFFT(NumSubc/2+1,:);中国通信网无限分享#Uxj*dnJ-sdSymEqtmp(2:NumSubc/2,:) = SymFFT(2:NumSubc/2,:);中国通信网无限分享zA G$N:?2Lfor m = 1:NumLoop中国通信网无限分享a3U qUl* for n = 1:NumSubc/2中国通信网无限分享$q _IWL%vTr Real = real(SymEqtmp(n,m);)S:L |3J+Irk0 Imag = imag(SymEqtmp(n,m);中国通信网无限分享BQD+?Sd R x-K6Yar oMA0 if( abs(Real -1) abs(Real +1)中国通信网无限分享d6f!| SG Yd SymDec(2*n-1,m) = 1;中国通信网无限分享v*sA-W/p(AC elseR,aR3l0N(j5x+?0 SymDec(2*n-1,m) = 0;%|;jAQl7i0 end if( abs(Imag -1) -1-i,01-1+i,10-1-i,11-1+i中国通信网无限分享&y,u5d(o6L uTestSymDec = zeros(NumSubc,NumLoop);中国通信网无限分享eOL)s0I3xVXQplTestSymEqtmp(1,:) = SymFFT(1,:)+i*SymFFT(NumSubc/2+1,:);b y.H9A3jo7V v6F0TestSymEqtmp(2:NumSubc/2,:) = SymFFT(2:NumSubc/2,:);中国通信网无限分享 C9j P.b0J(b a.jTestSymEqtmp1 = reshape(TestSymEqtmp,1,NumSubc*NumLoop/2);:Ttb,g ow(VdU:R.J0min_d = zeros(size(TestSymEqtmp1);GTn7/b*q(s)HS0min_ddd = zeros(1,NumSubc*NumLoop);0o5|nv bn0d = zeros(4,1);中国通信网无限分享Kcs&f;e f(emin_index = 0;ar!T x0i8H%.w HD0for ii = 1:1:(NumSubc*NumLoop/2)7MhZ#j$qy-m70 for jj = 1:4中国通信网无限分享7E*rEq/g+L,J d(jj) = abs(TestSymEqtmp(ii) - QAMTable(jj);a k,9eA1|%B,y0 end中国通信网无限分享a f8T7| YW min_d(ii),min_index = min(d);$p8GsK gdSD0% % Y,I = MIN(X) returns the indices of the minimum values in vector I. 中国通信网无限分享 U(J i REJ switch min_index中国通信网无限分享r)j7W*p,b(A case 1中国通信网无限分享 hsoB2jt(i min_ddd(2*ii-1) = 0 ;xC x:y!tS Q7|%n0 min_ddd(2*ii) = 0 ;中国通信网无限分享 SG2Y&|*s8P+QB case 23&V ;uC_0 min_ddd(2*ii-1) = 0 ;t2oc3opmE2J0 min_ddd(2*ii) = 1 ;iwZ$OH?.H0 case 3daEyQ(wl0 min_ddd(2*ii-1) = 1 ;中国通信网无限分享A&t,byGxt min_ddd(2*ii) = 0 ;-G1Y(O D0D#UTL0 case 4中国通信网无限分享fE&eWpEd min_ddd(2*ii-1) = 1 ;?:|,fYx6m0 min_ddd(2*ii) = 1 ;中国通信网无限分享 p!s6S%f(Nz otherwisen*yq-p0H1Xm-G0 fprintf(Impossible error! nn);中国通信网无限分享DdF;WSJl end中国通信网无限分享-M5u/mbend_!O; 2c0%-1e7PjJ Q-B0% 函数说明：中国通信网无限分享(ul JQ J)jVk-M&g-E% % C = min(A) returns the smallest elements along different dimensions of an中国通信网无限分享 fL)GK x dk% % array.v?Dm;e0% % If A is a vector, min(A) returns the smallest element in A.中国通信网无限分享-lX_s W-K% % If A is a matrix, min(A) treats the columns of A as vectors, returning a row中国通信网无限分享 r7qF4G2|Y3pH1*k% % vector containing the minimum element from each column.% % C,I = min(.) finds the indices of the minimum values of A, and returns中国通信网无限分享u(j*h6vvGi9rLLE% % them in output vector I. If there are several identical minimum values, the#I8Yh9oF?+?:Oi0% % index of the first one found is returned.% Bit Error中国通信网无限分享de6 trF&CBitsRx = zeros(1,NumSubc*NumLoop);中国通信网无限分享2R4ko9IM%Mq5_BitsRx = SymDec(:).;中国通信网无限分享.3OG/cNum,Ber = symerr(BitsTx,BitsRx)ff eY)kO#S!q0BerSnrTable(snr+1,2) = Num ;中国通信网无限分享5EPyIQMq!?BerSnrTable(snr+1,3) = Ber ;7hnp5F k6|)a)P1dN8|0end%-中国通信网无限分享e8Ys2o%s% Test by lavabin中国通信网无限分享W_fraNsif min_ddd = BitsRx 中国通信网无限分享 k5I Z&uD3A2k fprintf(DeQAM two ways the same results nn);中国通信网无限分享h;c%|m On!JAelse中国通信网无限分享kgVZ5_ fprintf(DeQAM two ways the different results);中国通信网无限分享8c2Y6hIEendA k4l|S(z-h0%-,EI+X)G_.Ot0figure(1);中国通信网无限分享Y(S B2o3N Usubplot(2,1,1);中国通信网无限分享N3 R y0%W5f)LEsemilogy(BerSnrTable(:,1),BerSnrTable(:,2),o-);中国通信网无限分享6wrgchU5itI 6ngsubplot(2,1,2);jvQ)QhbD$w0semilogy(BerSnrTable(:,1),BerSnrTable(:,3),o-);中国通信网无限分享uy t?t6q L%-time_of_sim = toc.s)KQ#m#O)gm0echo on;$Nw;u0ce0% - %aJe-O3g9x0% The END %xT6zq4l/e$o.u%z0% - %中国通信网无限分享aB2R4w&XG中国通信网无限分享,Kn.Kq Wd:X(D&aoh i% 本程序中得到的收端OFDM信号的频谱波形，是与其发端信号的排步有关的。在发端的中国通信网无限分享V$Tsp/ln% 载波安排上，128个载波有前后各32个载波是null载波(如果这前后各32各载波是带外频段，中国通信网无限分享O9F X/n-w9uI0bH% 那么理论上它们都应该是零！)，中间的64个载波是数据载波。这样的排步很明显就是一个x(VfT8T5w0% 两边低，中间高的频谱形式。所以，收端也应该是这个轮廓。中国通信网无限分享0p iF$l _E6dE p&L9PZTg7xQz,w0clc;clear all;close all;echo off;tic;!F!Wbv7s0% -中国通信网无限分享0R/uVesOo% Parameter Definition,LLRu d;Qt0% -中国通信网无限分享mW&ylH aFd = 1; % symbol rate (1Hz)o(o8r:6U0Fs = 1*Fd; % number of sample per symbolQ p0 W:l0M = 4; % kind(range) of symbol (0,1,2,3)Ndata = 1024; % all transmitted data symbol 中国通信网无限分享fl yim%4qSdata = 64; % 64 data symbol per frame to ifft中国通信网无限分享ZoUVXtndSlen = 128; % 128 length symbol for IFFT 中国通信网无限分享2K9DH5w_3Nsym = Ndata/Sdata; % number of frames - Nsym frame中国通信网无限分享i Cwd0HGIlen = 144; % symbol with GI insertion GIlen = Slen + GI:.O Q3LHC0GI = 16; % guard interval length% -中国通信网无限分享5I8t)xH% Vector Initialization中国通信网无限分享x(_$o2CQU% -中国通信网无限分享Ab!n&:h/X PDX = zeros(Ndata,1);中国通信网无限分享)s P czdY1 = zeros(Ndata,1);cw-| X+?c7n6Ii0Y2 = zeros(Ndata,1);vovd O(u!H(d0Y3 = zeros(Slen,1);中国通信网无限分享0