%%16QAM
%%等效基带调制
clc;
clear all;
close all;%%关闭所有窗口，比如之前画的图
nsymbol = 10000;%%每种信噪比下符号数的发送符号数，10^6 个数
errornumber = zeros(1,10);
errorratio = zeros(1,10);
data = randi([0,1],1,4*nsymbol);%%产生 1 行，4*nsymbol 列均匀分布的随机数
data_mod1 = zeros(1,nsymbol);%%各参量初始化
data_mod2 = zeros(1,nsymbol);
data_demod1 = zeros(1,nsymbol);
data_demod2 = zeros(1,nsymbol);
data_demod3 = zeros(1,nsymbol);
data_demod4 = zeros(1,nsymbol);
s_receive1 = zeros(1,nsymbol);
s_receive2 = zeros(1,nsymbol);

for i = 1:nsymbol %%格雷码调制 ...