GMSK调制解调系统的matlab性能仿真,对比维特比解调,1bit差分解调,2bit差分解调

1.前言

GMSK(Gaussian Minimum Shift Keying，高斯最小频移键控)是一种连续相位调制技术，基于MSK调制改进而来，通过高斯滤波器对基带信号预滤波，降低旁瓣功率，提高频谱效率。在本课题中，我们将对比GMSK的维特比解调,1比特差分解调,2bit差分解调三种解调方法。

2.算法运行效果图预览

(完整程序运行后无水印)

3.算法运行软件版本

Matlab2024b(推荐)或者matlab2022a

4.部分核心程序

（完整版代码包含中文注释和操作步骤视频）

    %解调，去载波N   = 300;  % 滤波器的阶数                                         F   = [0,fc-1000,fc+1000,Fs/2]*2/Fs;A   = [1,1,0,0];lpf = firls(N,F,A);I_dem = XNmod.*cos(2*pi*fc*t)*2;I_dem = conv(I_dem,lpf);I_dem = I_dem(N/2+1:N/2+length(I_temp));Q_dem = XNmod.*sin(2*pi*fc*t)*2;Q_dem = conv(Q_dem,lpf);Q_dem =-Q_dem(N/2+1:N/2+length(I_temp));%抽取I_dem_out = zeros(1,length(I_dem)/4);         Q_dem_out = zeros(1,length(Q_dem)/4);for i=1:length(I_dem_out)I_dem_out(i)=I_dem(4*(i-1)+1);Q_dem_out(i)=Q_dem(4*(i-1)+1);end%维特比算法decision = func_vitbi(I_dem_out,Q_dem_out,Lsymb,Nsamp,Nstate,state_all,State2,L,qt,9);%计算误码率[num,ber(SNR+1)] = symerr(dat1,decision);
01_0252m