Error Performance Analysis of DF and AF Multi-way Relay Networks with BPSK Modulation

摘要

In this paper, we analyze the error performance of decode and forward (DF)and amplify and forward (AF) multi-way relay networks (MWRN). We consider aMWRN with pair-wise data exchange protocol using binary phase shift keying(BPSK) modulation in both additive white Gaussian noise (AWGN) and Rayleighfading channels. We quantify the possible error events in an $L$-user DF or AFMWRN and derive accurate asymptotic bounds on the probability for the generalcase that a user incorrectly decodes the messages of exactly $k$($k\in[1,L-1]$) users. We show that at high signal-to-noise ratio (SNR), thehigher order error events ($k\geq 3$) are less probable in AF MWRN, but allerror events are equally probable in a DF MWRN. We derive the average BER of auser in a DF or AF MWRN in both AWGN and Rayleigh fading channels under highSNR conditions. Simulation results validate the correctness of the derivedexpressions. Our results show that at medium to high SNR, DF MWRN providesbetter error performance than AF MWRN in AWGN channels even with a large numberof users (for example, L=100). Whereas, AF MWRN outperforms DF MWRN in Rayleighfading channels even for much smaller number of users (for example, $L > 10$).