So far, we got three simulation results:
Comparison between AWGN channel and fading channel

As can be seen form this figure, the capacity of the AWGN channel is better than the Rayleigh fading channel , as the value of singal noise ratio increases, the channel capacity is higher and higher. 

Bipolar NRZ in AWGN channel

Unipolar NRZ in AWGN channel

Compare the bit error ratio in AWGN channel with different model, BER of binary bipolar NRZ signal is smaller than the unipolar, in addition  the error rate decrease inversely with the SNR.