求助:qpsk,NRZ中心频率
T=1; % symbol durationSNR=0; % signal to noise ratio
fc=6 /T; % carrier frequence
ml=2; % modulation of level ml=1 BPSK,ml=2 QPSK
nb=100; % number of transmiting bits
delta_T=T/100; % sampling interval
fs=1/delta_T; % sampling frequency
t=0:delta_T:nb*T-delta_T;
N=length(t); % number of samples
% generate source data
data=randn(1,nb)>0.5;
datanrz=data.*2-1; % translate source data into NRZ code
data1=zeros(1,nb/delta_T);
for q=1:nb
data1((q-1)/delta_T+1:q/delta_T)=datanrz(q);
end % transmiting signal
data2=abs(fft(data1));
figure(1)
plot(data1),title('baseband signal');
figure(2)
plot(fftshift(data2)),title('baseband signal spectrum');
中心频率为什么为5000?
迷茫很久了,天天想,就是想不出.离散序列的频率是如何算的?程序已看懂,100个NRZ
通过这句
for q=1:nb
data1((q-1)/delta_T+1:q/delta_T)=datanrz(q);
end % transmiting signal
变为"100个1或-1,100个1或-1,100个1或-1…… “,总共100个 5000的单位不是hz,需要转换一下 请问如何转换?
仿真结果和理论分析相符就行了,看着图却解释不清
谢谢,脑子里整天有这个问题的影子
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