AWGN信道输出实数而不是复数

Question

当我在Matlab中运行我的代码时，我会得到这个错误。但我可以在链路https://www.mathworks.com/help/comm/ref/comm.rsencoder-class.html上运行“通过AWGN信道传输缩短的RS编码，256-QAM调制的符号流”，没有问题。

当我在代码中检查变量chnData中的值时，我会看到实数。当我在示例代码中检查变量chan中的值时，我会看到复数。我的密码怎么了？

PS:我正在开发R2012b，通讯工具箱版本是5.3。

错误消息：

Error using comm.RectangularQAMDemodulator/step
Complexity mismatch with input 1; expected complex, got real.
Error in project (line 41)
            demData = step(qamDemodulator, chnData);

我的代码：

close all;
clear all;
clc;
enableRS = 1;
M = 16; % M-QAM
N = 15; % Reed-Solomon Coding : codelength
K = 11; % Reed-Solomon Coding : wordlength
EbNo = [-5:5]; % AWGN Channel : bit-to-noise energy
bps = log2(M); % AWGN Channel : bits per symbol
rsEncoder = comm.RSEncoder('CodewordLength', N, ...
                           'MessageLength',  K);
rsDecoder = comm.RSDecoder('CodewordLength', N, ...
                           'MessageLength',  K);
qamModulator = comm.RectangularQAMModulator('ModulationOrder', M, ...
                                            'NormalizationMethod', 'Average power');
qamDemodulator = comm.RectangularQAMDemodulator('ModulationOrder', M, ...
                                                'NormalizationMethod', 'Average power');
awgnChannel = comm.AWGNChannel('EbNo', EbNo, ...
                               'BitsPerSymbol', bps);
errorRate = comm.ErrorRate;
[H W] = size(EbNo);
errors = zeros(1,W);
for e = 1:W
    error = zeros(1,3);
    awgnChannel.EbNo = EbNo(e);
    if enableRS == 1
        while error(2) < 100 && error(3) < 1e7
             txData = randi([0 1], K, bps);
            encData = step(rsEncoder, bi2de(txData));
            modData = step(qamModulator, encData);
            chnData = step(awgnChannel, encData);
            demData = step(qamDemodulator, chnData);
            decData = step(rsDecoder, de2bi(demData));
             rxData = decData;
               error = step(errorRate, bi2de(txData), bi2de(rxData));
        end
    end
    errors(e) = error(1);
end
if enableRS == 1
    semilogy(EbNo, errors);
    grid;
    xlabel('Eb/No (db)');
    ylabel('Bit Error Rate');
    hold;
    uncoded = berawgn(EbNo, 'qam', M);
    semilogy(EbNo, uncoded);
end

Answer 1

发现了错误！现在修好了。

modData = step(qamModulator, encData);
chnData = step(awgnChannel, encData); // Should have been modData