matlab编程代做GMSK系统仿真资料下载.pdf

matlab编程代做GMSK系统仿真资料下载.pdf

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%1为差分编码的初始参考值fori=2:

length（data）data_diff（i）=data_diff（i-1）*data（i）;

end%*functiongt,qt=gauss_filter（Bb,Tb,fs,sample_number）%高斯滤波器%*%Bb滤波器的3dB带宽%Tb码元时间%fs采样速率%sample_number采样个数%*%Rb=16000;

%Tb=1/16000;

%sample_number=8;

%fs=sample_number*Rb;

%Bb=0.25/Tb;

%-%g（t）irfn=3;

%截取irfn个Tb区间n=irfn*sample_number;

mid=（n./2）;

t=-mid/fs:

1/fs:

mid/fs;

gt=1/2*（erf（-sqrt（2/log

（2）*pi*Bb*（t-1/2*Tb）+erf（sqrt（2/log

（2）*pi*Bb*（t+1/2*Tb）;

%*%-%q（t）qt=zeros（1,irfn*sample_number）;

fori=1:

irfn*sample_numberforj=1:

iqt（i）=qt（i）+gt（j）/sample_number/2;

end;

%*%GMSK调制，一比特差分解调clearallcloseall%-%参数设置data_len=30000;

%码元个数sample_number=8;

%采样个数Rb=24000;

%码元速率fc=96000;

%载波频率alpha=0.25;

%BbTb值%*%-%随机产生传输信号data=rand_binary（data_len）;

%*%-%GMSK基带调制signal_out,I_out,Q_out,phase,gt,qt=mod_gmsk（data,data_len,sample_number,Rb,alpha）;

%*%-%中频搬移multi=fc/Rb;

I_temp=interp（I_out,multi）;

Q_temp=interp（Q_out,multi）;

Fs=fc*sample_number;

t=1/Fs:

1/Fs:

length（I_temp）*1/Fs;

signal_i=I_temp.*cos（2*pi*fc*t）;

signal_q=Q_temp.*sin（2*pi*fc*t）;

signal_mod_i=I_temp.*cos（2*pi*fc*t）-Q_temp.*sin（2*pi*fc*t）;

signal_mod_q=I_temp.*sin（2*pi*fc*t）+Q_temp.*cos（2*pi*fc*t）;

%*%-%加噪声forSNR=0:

16%signal_mod1=awgn（signal_mod_i+j*signal_mod_q,SNR）;

noise=randn（1,length（signal_mod_i）;

b=0.2;

c=0.22;

d=0.28;

e=0.3;

F1=0,b,c,d,e,1;

A1=0,0,1,1,0,0;

bpf=firls（300,F1,A1）;

noise1=conv（noise,bpf）;

noise_out=noise1（150+1:

150+length（signal_mod_i）;

Power_noise=sum（noise_out.2）;

Power_signal_i=sum（signal_mod_i.2）;

Power_signal_q=sum（signal_mod_q.2）;

Coe_SNR_i=sqrt（1*Power_signal_i/Power_noise/（10（SNR/10）;

Coe_SNR_q=sqrt（1*Power_signal_q/Power_noise/（10（SNR/10）;

signal_mod1=（signal_mod_i+（Coe_SNR_i）*noise_out）+j*（signal_mod_q+（Coe_SNR_q）*noise_out）;

%加入噪声以后的信号%-%一比特延迟差分cospart=real（signal_mod1）;

sinpart=imag（signal_mod1）;

delay=zeros（1,multi*sample_number）sinpart（1:

data_len*sample_number*multi-multi*sample_number）;

cha=-delay.*cospart;

N=300;

%滤波器的阶数为（N+1）F=0,fc,fc,Fs/2*2/Fs;

A=1,1,0,0;

lpf=firls（N,F,A）;

dem1=conv（cha,lpf）;

dem=dem1（N/2+1:

N/2+length（cha）;

%*%-%抽样判决fori=1:

data_lendemod_data（i）=dem（i*multi*sample_number）0;

enddemod_data=2*demod_data-1;

%*%-%计算误码率num,ber（SNR+1）=symerr（demod_data（2:

data_len）,data（2:

data_len）;

%*end%*%-%误码率曲线semilogy（0:

16,ber,r*-）;

%*amp=100.6900.24;

dj=length（amp）;

djsignal_mod_i=signal_mod_i+amp（i）*delay（signal_mod_i,i-1,sample_number）;

signal_mod_q=signal_mod_q+amp（i）*delay（signal_mod_q,i-1,sample_number）;

end%-%加噪声forSNR=0:

%*fc=fc+500;

%-%加噪声forSNR=0:

20%signal_mod1=awgn（signal_mod_i+j*sign