On the Optimal Power Allocation for Two-Way Full-Duplex AF Relay Networks

• Main Authors: Li, Jyun-Wei, 李俊緯
• Other Authors: Lin, Che
• Format: Others
• Language: en_US
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/30695726635884654085

碩士 === 國立清華大學 === 通訊工程研究所 === 104 === This thesis investigates the optimal power allocation that maximizes the system utility for a full-duplex (FD) amplify-and-forward (AF) relaying two-way relay network (TWRN) with a rate outage and a power constraint. Both cases of an individual and a sum power constraint are considered. To formulate the corresponding optimization problem, closed-form expressions of outage probabilities are needed. With FD transceivers, the derivation of such closed-form expressions become too involved. Thus, approximate closed-form expressions were derived instead. The resulting optimal problem is still non-convex and difficult to solve. Via solving a series of approximate convex problems, a successive convex approximation (SCA) algorithm was proposed. Our simulation results demonstrate the accuracy of the approximate closed-form expressions of outage probabilities and that the proposed SCA algorithm achieves near-optimal performance and significantly outperforms the full power allocation under the individual power constraint and uniform power allocation under the sum power constraint both in system utility and in power consumption. Our results further show that simultaneous power transmission for all relay nodes with judicious power allocation generated by the SCA algorithm achieves as high as 46% of performance gain over the relay selection scheme. A tradeoff between the FD system and the half-duplex (HD) system with respect to the residual interference was also observed. We can also observe that not only the residual self-interference but also cross-link interference is a factor that degrades the system performance for a FD system.