%?clear?all?variables?
clear;?
?
sig_num?=?300;?
fd?=?1;?
fs?=?7;?
N?=?64;?
fm?=?10;??%unit:?1Hz?
Rs?=?1;??%unit:?1MHz?
Ts?=?1/Rs;?
?
%?generate?random?QPSK?signal?
qpsk_D=randint（sig_num14）;?
qpsk_C=dmodce（qpsk_Dfdfs‘psk‘4）;?
qpsk_flt?=?rcosflt（qpsk_Cfdfs）;?
?
%?draw?eye?diagram?and?scatter?plot?of?QPSK?signal?
qpsk=qpsk_flt（1+3*fs:end-3*fs）;?
%eyediagram（qpsk2*fs2*fs）;?
%scatterplot（qpskfs）;?
?
%?QPSK?signal?passes?through?AWGN?channel?
snr=8;?
qpsk_AWGN_C=awgn（qpsk_Csnr）;?
qpsk_AWGN_flt=rcosflt（qpsk_AWGN_Cfdfs）;?
qpsk_AWGN=qpsk_AWGN_flt（1+3*fs:end-3*fs）;?
%eyediagram（qpsk_AWGN2*fs2*fs0‘r-‘）;?
%scatterplot（qpsk_AWGNfs0‘r.‘）;?

%?generate?Doppler?power?spectrum?
deltaf?=?2*fm/（N-1）;?
T?=?1/deltaf;?
sf0?=?1.5/（pi*fm）;?
for?n?=?1:（N-2）/2