BER-Based Comparison between AF and DF in Three-Terminal Relay Cooperative Communication with BPSK Modulation
Xianru Liu, Wenhao Du · 2016
In the future millimeter-wave small-cell communication systems, relay cooperation is deemed as one of the promising techniques to realize green communication. In relay cooperative system, the selected relaying mode determines the system performance in some extent. For the commonly used modes, amplify-and-forward (AF) and decode-and-forward (DF), which one should be taken in specific scenario? In this paper, for three-terminal relay network, taking Bit-Error-Rate(BER) as metric, the performance of AF and DF are analyzed and compared when binary-phase-shift-keying (BPSK) mode is taken. The scenario with and without direct link between source and destination are both considered. After the closed form expressions for BER are obtained in mathematics, they are compared under the same channel conditions. Then, it is proved that DF mode is always better than AF in BER performance when BPSK scheme is taken. For several representative communication scenarios, Monte Carlo simulations are carried out to further verify the conclusion.