'--snr', type=float, default=1., help='the maximum SNR'
时间: 2024-01-27 15:05:47 浏览: 18
This parameter sets the maximum signal-to-noise ratio (SNR) for a given audio signal. SNR is a measure of the strength of the signal relative to the amount of noise present in the audio. A higher SNR means that the signal is stronger relative to the noise, and therefore the audio is clearer and easier to understand. By setting a maximum SNR, the program can ensure that the audio output is of a consistent quality and not excessively noisy. The default value for this parameter is 1.0, which means that the signal is only slightly stronger than the noise. This value can be adjusted depending on the specific needs of the user.
相关问题
clear all; Tx_n = 2; Rx_n = 2; %---------------SNR vector------------- SNRindB = 2:1:10; SNR = 10.^(SNRindB/10); %------------modulation----------------- L = 20000; BitPerSymbol = 2; s0 = randi(1,1,L); h_1 = pskmod('M',2^BitPerSymbol,'gray','InputType','Bit'); s = modulate(h_1,s0.').'; %-------------seperation-------------- s1 = zeros(Tx_n,length(s)); for ii = 1:Tx_n:(length(s)-1) %stbc s1(1,ii) = s(ii); s1(2,ii) = s(ii+1); s1(1,ii+1) = conj(s(ii+1)); s1(2,ii+1) = -conj(s(ii)); end L1 = length(s1(1,:)); %----------noise and channel-------------- S = zeros(2, 2); S1 = zeros(1, L1); rx = zeros(L, 1); BER = zeros(length(SNR), 1); SER = zeros(length(SNR), 1); for ii = 1:length(SNR) sigma = 1/(sqrt(2*SNR(ii))); for iii = 1:2:L1-1 noise = sigma*(randn(Rx_n,1)+1i*randn(Rx_n,1)); H = sqrt(0.5)*(randn(Rx_n, Tx_n) + 1i*randn(Rx_n, Tx_n)); %----------add noise------------------------ R1 = H*s1(:,iii)+noise; %接收信号1,Rx_n * 1 R2 = H*s1(:,iii+1)+noise; %接收信号2,Rx_n * 1 %----------receive MMSE------------------- hh = H(:,1).*conj(H(:,1)) + H(:,2).*conj(H(:,2)); S_t1 = conj(H(:,1)).*R1-H(:,2).*conj(R2); S_t2 = conj(H(:,2)).*R1+H(:,1).*conj(R2); S(:,1) = S_t1./hh; S(:,2) = S_t2./hh; for si = 1:1:Rx_n S1(1,iii) = S1(1,iii) + S(si,1); S1(1,iii+1) = S1(1,iii+1) + S(si,2); end S1(1,iii) = S1(1,iii)/Rx_n; S1(1,iii+1) = S1(1,iii+1)/Rx_n; end h_2 = modem.pskdemod('M', 2^BitPerSymbol,'SymbolOrder','gray', 'OutputType', 'Bit'); rx = demodulate(h_2,S1.'); remod = modulate(h_1, rx); %------------calculate ber--------------------------- SER(ii,:) = symerr(remod.',s)/L1; BER(ii,:) = biterr(rx.',s0)/L; end semilogy(SNRindB,BER,'g-^'); hold on; semilogy(SNRindB,SER,'m-^'); grid on; xlabel('SNR(dB)'); ylabel('BER'); title('STBC SNR-BER curve'); legend('BER 2x1','SER 2x1','BER 2x2','SER 2x2');代码有误,帮忙修改一下
以下是修改后的代码,主要是将`pskmod`函数的参数传递方式改正、修正一些语法错误和变量名错误:
```matlab
clear all;
Tx_n = 2;
Rx_n = 2;
%---------------SNR vector-------------
SNRindB = 2:1:10;
SNR = 10.^(SNRindB/10);
%------------modulation-----------------
L = 20000;
BitPerSymbol = 2;
s0 = randi([0 1],1,L);
h_1 = pskmod(s0,2^BitPerSymbol,pi/4,'gray');
%-------------seperation--------------
s1 = zeros(Tx_n,length(h_1));
for ii = 1:Tx_n:(length(h_1)-1)
%stbc
s1(1,ii) = h_1(ii);
s1(2,ii) = h_1(ii+1);
s1(1,ii+1) = -conj(h_1(ii+1));
s1(2,ii+1) = conj(h_1(ii));
end
L1 = length(s1(1,:));
%----------noise and channel--------------
S = zeros(2, 2);
S1 = zeros(1, L1);
rx = zeros(L, 1);
BER = zeros(length(SNR), 1);
SER = zeros(length(SNR), 1);
for ii = 1:length(SNR)
sigma = 1/(sqrt(2*SNR(ii)));
for iii = 1:2:L1-1
noise = sigma*(randn(Rx_n,1)+1i*randn(Rx_n,1));
H = sqrt(0.5)*(randn(Rx_n, Tx_n) + 1i*randn(Rx_n, Tx_n));
%----------add noise------------------------
R1 = H*s1(:,iii)+noise; %接收信号1,Rx_n * 1
R2 = H*s1(:,iii+1)+noise; %接收信号2,Rx_n * 1
%----------receive MMSE-------------------
hh = H(:,1).*conj(H(:,1)) + H(:,2).*conj(H(:,2));
S_t1 = conj(H(:,1)).*R1-H(:,2).*conj(R2);
S_t2 = conj(H(:,2)).*R1+H(:,1).*conj(R2);
S(:,1) = S_t1./hh;
S(:,2) = S_t2./hh;
for si = 1:1:Rx_n
S1(1,iii) = S1(1,iii) + S(si,1);
S1(1,iii+1) = S1(1,iii+1) + S(si,2);
end
S1(1,iii) = S1(1,iii)/Rx_n;
S1(1,iii+1) = S1(1,iii+1)/Rx_n;
end
h_2 = modem.pskdemod('M',2^BitPerSymbol,'SymbolOrder','gray', 'OutputType', 'Bit');
rx = demodulate(h_2,S1.');
remod = pskmod(rx,2^BitPerSymbol,pi/4,'gray');
%------------calculate ber---------------------------
SER(ii,:) = symerr(remod.',h_1)/L1;
BER(ii,:) = biterr(rx.',s0)/L;
end
semilogy(SNRindB,BER,'g-^');
hold on;
semilogy(SNRindB,SER,'m-^');
grid on;
xlabel('SNR(dB)');
ylabel('BER');
title('STBC SNR-BER curve');
legend('BER 2x1','SER 2x1','BER 2x2','SER 2x2');
```
修正后的代码应该可以正常运行并绘制出STBC的SNR-BER曲线。
for snr=1:1:length(ave_snr)
这是一个 for 循环,其中 snr 的初始值为 1,每次循环加 1,直到 snr 的值等于 ave_snr 的长度为止。在循环体内可以对 snr 进行操作或使用,例如:
```
for snr = 1:1:length(ave_snr)
disp(['当前的 SNR 值为:', num2str(ave_snr(snr))]);
end
```
这个循环将依次输出 ave_snr 数组中每个元素对应的 SNR 值。注意,这里的 `num2str` 函数是将数字转为字符串的函数,这样才能与字符串进行拼接输出。