msk_system.m

系统化的MSK算法

%二进制


clear;
clc;


Rb=24000;
Fs=4*Rb;
N_sample=Fs/Rb;%一个比特空间内的采样个数

M=2;
N_observe=10;
h=1/2;
Num_pack=10;
Error_ratio=[];

for snr=0:7
Error_num=0;

for number_index=1:Num_pack
snr
number_index

N_data=1000;
Data=round(rand(1,N_data));
Data_temp=2*Data-1;

Modu_out=CPMbasebandmod(Data_temp,Fs,Rb,N_observe,h);

sigma=sqrt(0.5*N_sample*10^(-snr/10));
N_signal=length(Modu_out);
real_signal=real(Modu_out);
imag_signal=imag(Modu_out);

r_real=real_signal+sigma*randn(1,N_signal);
r_imag=imag_signal+sigma*randn(1,N_signal);
r_receive=r_real+j*r_imag;


Det_out=CPMbasebanddem(r_receive,Fs,Rb,N_observe,h);
Det_out=(Det_out+1)/2;

[Error_num_temp,Error_ratio_temp]=biterr(Data,Det_out);

Error_num=Error_num+Error_num_temp;
Error_num_temp

end%for number_index

Error_ratio_temp=Error_num/(Num_pack*N_data);

Error_ratio=[Error_ratio,Error_ratio_temp];

end%for snr

snr=0:7;
semilogy(snr,Error_ratio);