Title: Outage-optimal power allocation for space-time cooperative network coding with amplify-and-forward protocol

Authors: Yan-cheng Ji; Guo-an Zhang; Xiao-ge Zhang; Xun Huang

Addresses: School of Electronics and Information, Nantong University, No. 9 Seyuan Road, 226019 Nantong, Jiangsu, China ' School of Electronics and Information, Nantong University, No. 9 Seyuan Road, 226019 Nantong, Jiangsu, China ' School of Electronics and Information, Nantong University, No. 9 Seyuan Road, 226019 Nantong, Jiangsu, China ' School of Electronics and Information, Nantong University, No. 9 Seyuan Road, 226019 Nantong, Jiangsu, China

Abstract: To improve the resource utilisation of traditional two-way wireless relay system, an optimal power allocation (OPA) algorithm for a space-time cooperative network coding scheme employing amplify-and-forward protocol (AF-ST-CNC) is proposed. The system performance in terms of outage probability and its approximation in high signal-to-noise (SNR) regimes are first derived, and with minimising the larger outage probability of the two sources, the optimal power factors are obtained by using an iterative algorithm. Moreover, the closed-form solutions of the optimal power allocation factor under some special scenarios are given. The proposed algorithm only needs the average channel gain information and has low computation complexity, which facilitates the practical implementation. Simulation results show that, the proposed F-ST-CNC with OPA algorithm outperforms the AF-ST-CNC with equal power allocation (EPA) algorithm and the space-time cooperative network coding scheme employing amplify-and-forward protocol (DF-ST-CNC) with OPA algorithm in terms of outage performance and symbol error rate (SER) performance.

Keywords: two-way relays; network coding; Alamouti space-time coding; outage probability; power allocation; cooperative networks; amplify-and-forward protocol; signal-to-noise ratio; SNR; simulation; symbol error rate; SER.

DOI: 10.1504/IJES.2013.057087

International Journal of Embedded Systems, 2013 Vol.5 No.3, pp.127 - 133

Received: 19 Nov 2012
Accepted: 26 May 2013
Published online: 19 Jul 2014 *

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