直流分量是什么_qam解调_qam 非相干(2)

程序如下：

%% Transmitted Signal

ytx = y;

%% Channel

% Send signal over an AWGN channel.

EbNo = 10; % In dB

snr = EbNo + 10*log10(k) - 10*log10(nsamp);

ynoisy = awgn(ytx,snr,measured);

%% Received Signal

yrx = ynoisy;

5、绘制星座图

对发射和接收信号利用scatterplot函数可显示信号星座图的样子及噪声对信号造成的失真程度。在该图中，横轴代表了信号的同相分量而纵轴代表了正交分量。

程序如下：

%% Modulation

y = modulate(modem.qammod(M),xsym); % Modulate using 16-QAM. %% Transmitted Signal

ytx = y;

%% Channel

% Send signal over an AWGN channel.

EbNo = 10; % In dB

snr = EbNo + 10*log10(k) - 10*log10(nsamp);

ynoisy = awgn(ytx,snr,measured);

%% Received Signal

yrx = ynoisy;

%% Scatter Plot

% Create scatter plot of noisy signal and transmitted

% signal on the same axes.

h = scatterplot(yrx(1:nsamp*5e3),nsamp,0,g.);

hold on;

scatterplot(ytx(1:5e3),1,0,k*,h);

title(Received Signal);

legend(Received Signal,Signal Constellation);

axis([-5 5 -5 5]); % Set axis ranges.

hold off;

运行结果如下：

6、16-QAM解调

对接收信号利用modem.deqammod对象的demodulate方法进行解调。解调结果为包含0到15之间整数的列向量。程序如下：

本文来自电脑杂谈，转载请注明本文网址：
http://www.pc-fly.com/a/tongxinshuyu/article-33930-2.html