SC_FDE仿真平台：卷积编码 -＞矩阵交织 -＞ QPSK调制 -＞插入导频 -＞插入CP -＞ RayleighFading-＞channel

末蓝、 2022-09-09 00:24 92阅读 0赞

% 主函数  
% 调用各子函数，建立SC\_FDE仿真平台  
% 数据输入 -> 卷积编码 -> 矩阵交织 -> QPSK调制 -> 插入导频 -> 插入CP -> RayleighFading  
% channel -> AWGN channel -> 去除CP -> FDE -> QPSK解调 -> 矩阵去交织 -> Viterbi译码

%-------------------------------------------------------------------------%  
% Clearing Workspace %  
%-------------------------------------------------------------------------%  
clear all;  
clc;  
close all;

%-------------------------------------------------------------------------%  
% Seeting the parameters %  
%-------------------------------------------------------------------------%  
M = 5; %仿真运行的信噪比点数  
FrameSize = 512; %每帧信息比特的大小  
FrameNum = 100; %发送的数据帧数  
interleave\_table = interleav\_matrix( ones(1,2\*FrameSize) ); %产生交织码表  
UW\_Num = 64; %独特字UW的大小  
UW\_Ge = UW\_Generate( UW\_Num ); %产生独特字序列  
trel = poly2trellis( 7,\[171 133\] ); %产生trelis  
tblen = 5\*7; %Traceback depth  
Ts = 1/480000; %输入Rayleigh channel的信号采样时间(s)  
Fd = 4; %Rayleigh channel的最大多普勒频移(HZ)  
tau = \[0 2.6\*10^-7\]; %Rayleigh channel的路径延时向量(s)  
pdb = \[0 -3\]; %Rayleigh channel的路径增益向量(dB)  
Rayleigh\_chan = rayleighchan( Ts,Fd,tau,pdb ); %Generate Rayleigh channel

% t = scatterplot(0); %Initialize scatter plot  
% h = scatterplot(0); %Initialize scatter plot

BER\_arry = zeros(16,FrameNum);

for SNR = 0:2:20

%---------------------------------------------------------------------%  
% SC-FDE %  
%---------------------------------------------------------------------%  
for ii = 1:1:FrameNum  
%-----------------------------------------------------------------%  
% Generate Transmit Signal & Convolutional Code %  
% & Matrix Interleaver & QPSK modulator %  
%-----------------------------------------------------------------%  
BitsTranstmp = randint(1,FrameSize);  
conv\_out = convenc( BitsTranstmp,trel );  
interleav\_out = interleaving( conv\_out,interleave\_table );  
QPSK\_out = psk( interleav\_out,2 );

%-----------------------------------------------------------------%  
% QPSK\_out -> insetting pilot -> insetting CP %  
%-----------------------------------------------------------------%  
Signal\_Tx = \[UW\_Ge,QPSK\_out,UW\_Ge\];

%-----------------------------------------------------------------%  
% Signal\_Tx -> Rayleigh channel -> AWGN channel %  
%-----------------------------------------------------------------%  
Rayleigh\_chan\_out = filter( Rayleigh\_chan,Signal\_Tx );  
Signal\_Rx = awgn( Rayleigh\_chan\_out,SNR );

%-----------------------------------------------------------------%  
% Signal\_Rx -> Deleting CP -> MMSE\_FDE %  
%-----------------------------------------------------------------%  
FDE\_in = Signal\_Rx( 1,1:(size(Signal\_Rx,2)-UW\_Num) );  
FDE\_out = MMSE\_FDE( FDE\_in,UW\_Ge );

%-----------------------------------------------------------------%  
% FDE\_out -> QPSK Demodulator -> Matrix Deinterleaver -> Viterbi %  
%-----------------------------------------------------------------%  
% h = scatterplot( FDE\_out,1,0,'b.',h); %plot the new plot  
% axis(\[-3 3 -3 3\]); %Adjust axis limits  
% title('scatter plot - after FDE');  
% grid;  
% drawnow; %refresh the image

deqpsk\_out = de\_qpsk( FDE\_out );  
deinterleav\_out = de\_interleaving( deqpsk\_out,interleave\_table );  
viterbi\_out = vitdec( deinterleav\_out,trel,tblen,'cont','hard' );

%-----------------------------------------------------------------%  
% Computing the BER %  
%-----------------------------------------------------------------%  
decoded = viterbi\_out(tblen+1:end);  
msg = BitsTranstmp(1:end-tblen);  
\[n,r\] = biterr( decoded,msg );  
% disp(\['The bit error rate is: ',num2str(r)\]);  
BER\_arry(SNR/2+1,ii) = r;  
end  
  
Ber(SNR/2+1) = sum( BER\_arry(SNR/2+1,:) )/FrameNum;  
disp(\['The SNR(dB) is : ',num2str(SNR), ' The BER is : ',num2str(Ber(SNR/2+1))\]);  
end

Snr = 0:2:20;  
figure;  
semilogy(Snr,Ber,'--\*');  
grid on;  
xlabel('SNR (dB)');  
ylabel('BER');  
title('SC-FDE rate 1/2 conv code QPSK');  
hold off