N=2^16;
%?M=64;
f1=0.15;
f2=0.17;
f3=0.26;
SNR1=20;
SNR2=25;
SNR3=30;
A1=10^（SNR1/20）;
A2=10^（SNR2/20）;
A3=10^（SNR3/20）;
L=100;
%?x=1-M:M-1;
signal1=A1*exp（1i*（2*pi*f1*（0:N-1）+unifrnd（02*pi）））;
signal2=A2*exp（1i*（2*pi*f2*（0:N-1）+unifrnd（02*pi）））;
signal3=A3*exp（1i*（2*pi*f3*（0:N-1）+unifrnd（02*pi）））;
noise=（randn（1N）+1i*randn（1N））/sqrt（2）;
un=signal1+signal2+signal3+noise;
p=8;
r0=xcorr（unp‘biased‘）;
r=r