# BER peroformance of MPSK and MQAM in Rayleigh fading channel

I have a question regarding bit error rate (BER) performance over the Rayleigh channel. I observed BER performance over the AWGN channel using Simulink in MATLAB. I used to change the "SNR" parameter in the AWGN block to get the BER.

What if I want to edit the block to get the BER but in Rayleigh fading channel (I want for every SNR, to get the BER). There is a Rayleigh fading channel block but I don't know how to use it.

I want to observe the BER performance of MPSK and MQAM over Rayleigh fading channel.

The figure below shows my blocks for observing BER in fading channel, the parameters in the fading block and my result.

In AWGN I generated binary bits, then modulated them by using the BPSK. After that I added the noise and then I demodulated it and finally I got the BER for every SNR.

However, I tried to edit it so I added the Multipath Rayleigh fading channel block to observe the BER in fading channel.

Here is the figure:

Regarding the Doppler spectrum type, there are several types: Jakes, Flat, Gaussian, Rounded, Restricted Jakes, Asymmetric Jakes, Bi-Gaussian, Bell and "specify as dialog parameter".

In the "Result" figure, the simulated one is the blue one (wrong) and the theoretical one (red) I got by using the "berfading" command, which is the correct one.

As you can see, my result in not correct. Are my blocks correct? Are there any parameters I should change, especially in the fading block, to get the correct result?

• Please don't re-post your question multiple times. I have closed your other question (which had less detail) as a duplicate of this question. Multiple questions fragments the answers that you may receive and makes it difficult for future visitors to understand the question and any potential answers.
– user16
Oct 5 '15 at 21:57