Performance analysis of amplify and forward protocol in the asymmetric channel

摘要

In the high-speed mobile environment, there exists many problems such as the Doppler effect and body loss. Those problems can make the communication under high-speed rail scene difficult. In this paper, high-speed rail scene is equivalent to asymmetric fading channels. That is to say, the system model consists of Rician and Rayleigh fading channels. On the basis of a single relay installed on the train, its known formulas can derive to the Signal to Noise Ratio (SNR), the Bit Error Rate (BER) and the Outage Probability of multiple relay with the amplify-and-forward protocol (AF). The simulation results show that the BER and the Outage Probability decrease while the SNR increases. Besides, the BER decreases more significant with the growing number of relays. It means that when the SNR is changed from 1 to 20, the decrease of BER is two orders of magnitude while N takes 2, and it is about 7 orders of magnitude while N takes 6.