Rate-optimal fair power allocation in complex field network coded relay communications

• Published in: Wireless networks Vol. 22; no. 4; pp. 1251 - 1267
• Main Authors: Eritmen, Kayhan, Keskinoz, Mehmet
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.05.2016; Springer Nature B.V
• Subjects: Analysis; Channels; Codes; Communication systems; Communications Engineering; Communications systems; Computer Communication Networks; Computer simulation; Degradation; Electrical Engineering; Energy management; Engineering; IT in Business; Mathematical models; Network topologies; Networks; Noise; Optimization; Policies; Receivers & amplifiers; Relay; Studies; Wireless networks; Decode-and-forward relaying; Complex field network coding; Power allocation; Relay communication; Average rate-fairness
• ISSN: 1022-0038; 1572-8196
• DOI: 10.1007/s11276-015-1031-z

In this paper, we consider the complex field network coded relay assisted communication (CFNC-RAC) channel. Although CFNC-RAC is spectrally efficient, its bit error rate performance is degraded by multi-access interference, which can be improved by appropriately allocating the user and relay powers. Since the fairness is an important factor for a practical multi-user communication system, we have proposed a rate-optimal fair power adaptation (ROFPA) technique in this work. The proposed ROFPA policy not only aims to maximize the average achievable sum-rate of CFNC-RAC under the use of the decode and forward relaying but also intends to satisfy the average rate-fairness restriction while taking the total power constraint and the network topology into account. We formulate the ROFPA as a non-convex optimization program and then derive an analytical solution for it. Extensive performance evaluation and numerical simulations validate that ROFPA method can provide significant sum-rate with considerable user fairness when compared to symbol-error-rate optimized (SER-OPT) policy proposed by Eritmen et al. (Wirel Netw, 2015 . doi:10.1007/s11276-015-0924-1).