Asymptotic BER analysis of threshold digital relaying schemes in cooperative wireless systems

Abstract

Abstract-Threshold relaying is an effective technique to achieve cooperative diversity in uncoded cooperative wireless networks, which suffer from error propagation due to detection errors at the relays. This paper analyzes the asymptotic end-toend (e2e) bit error rate (BER) of threshold digital relaying. A three node network with a source, destination and relay and with links experiencing independent Rayleigh fading is considered. It is shown that, as the average link signal-to-noise ratios (SNR) are increased simultaneously, the optimal threshold that minimizes the e2e BER increases as log(SNR). The resulting e2e BER decreases as log(SNR)/SNR 2 . Moreover, any threshold of the form log(c SNR), where c is a positive constant, achieves the same order of e2e BER as the one achieved by the optimal threshold and provides dual diversity. A value of c that performs very close to the optimal threshold is also proposed.Index Terms-Cooperative diversity relaying, threshold maximum ratio combining, diversity order, selective digital relaying, SNR based selective relaying, multihop communication.

Threshold Selection for SNR-based Selective Digital Relaying in Cooperative Wireless Networks

“…It is observed that simple digital relaying and direct transmission (i.e., no relay) have the same slope that is equal to 1, while the rest of relaying schemes have a common slope larger than 1, indicating cooperative diversity gains. The asymptotic diversity gains achieved by SNR-based selective relaying is studied in [15]. Fig.…”

“…The numerical results of our present paper hints that the latter conclusion is due to the particular choice of the scaling factor rather than the limitation of on-off power control; we observe that, if it is done intelligently, on-off power control can increase the slope of the e2e BER curve, (i.e., the diversity order) compared to simple digital relaying. In [15], it is shown that the SNR-based selective relaying achieves dual diversity.…”

Performance analysis of threshold digital relaying M2M cooperative networks

“…Approximations for the optimal thresholds that minimize the E2E BER and the resulting performance were derived analytically for PSK modulation. In [10], the asymptotic E2E BER of cooperative systems with TDR over Rayleigh fading channels was derived. It was shown that as the average link SNRs increase, the optimal threshold that minimizes the E2E BER increases.…”

Performance analysis of adaptive decode-and-forward relaying in noncoherent cooperative networks

“…Cooperative (or relay) diversity is attractive for such networks, i.e., networks with mobile terminals having single-antenna transceivers, since it is able to achieve spatial diversity. The basic idea is that a source node transmits information to the destination not only through a direct link but also through the relay links [2][3][4][5][6][7][8][9]. Cooperative protocols have been classified into *Correspondence: ha.nguyen@ttu.edu.vn 1 School of Engineering, Tan Tao University, Tan Duc E-city, Duc Hoa, Long An, Vietnam Full list of author information is available at the end of the article three main groups: amplify-and-forward (AF), decodeand-forward (DF), and compress-and-forward (CF) [2,10].…”