simulink AWGN信道使用要点

1.（1）在Columns as channels (frame based)模式下，噪声的添加方式The block adds frames of length-M Gaussian noise to each of the N channels, using a distinct random distribution per channel.
（2）Changing the symbol period in the AWGN Channel block affects the variance of the noise added per sample, which also causes a change in the final error rate.
（3）A good rule of thumb for selecting the Symbol period value is to set it to be what you model as the symbol period in the model. The value would depend upon what constitutes a symbol and what the oversampling applied to it is (e.g., a symbol could have 3 bits and be oversampled by 4).

2. Eb/No, Es/No和SNR
   Eb/No, the ratio of bit energy to noise power spectral density
   Es/No, the ratio of signal energy to noise power spectral density
   SNR, the ratio of signal power to noise power

3.Relationship Among Eb/No, Es/No, and SNR Modes
（1）For uncoded complex input signals, the AWGN Channel block relates Eb/N0, Es/N0, and SNR according to the following equations:

（2）For real signal inputs, the AWGN Channel block relates Es/N0 and SNR according to the following equation:

注：请注意，实信号下的关系式与复信号下相应的关系式相差2倍。这是因为该模块用N0/2 Watts/Hz作为实际输入信号的噪声功率谱密度，而复信号的噪声功率谱密度为N0 Watts/Hz 。

4.Number of bits per symbol 指每符号比特数；
Symbol period (s) 以秒为单位的符号持续时间；