作者itismystyle (徵bass手一枚)
看板comm_and_RF
标题[问题] 关於synchronization
时间Thu Nov 29 02:18:49 2007
有个MATLAB code
花了我不少时间研究
我不太懂这回圈的机制(PLL)
有没有大大能为我解答 QQ
for k = 1:Nsim
%% carrier compensation
y = r(k)*derotator;
% decision
d = Const(qamdemod(y,QAM)+1);
%% phase detector
pd = -imag(conj(y).*d);
%% loop filter
omega = omega+ki*pd;
if omega>0.124,omega = 0.124;end
if omega<-0.124,omega = -0.124;end
phe = kp*pd+omega;
% Generate derotator to compensate the constellation rotaion caused by CFO.
theta = mod(theta-phe,1);
derotator = exp(j*theta*2*pi);
%% record the simulation data
Omega(k) = omega;
out(k) = y;
end
完整的code附上
http://www.badongo.com/file/5334833
这跑出来的结果似乎有点问题耶
高SNR情况下 解调会错更严重
这是怎麽一回事
是code有问题吗?
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