Optimal Asymmetric Resource Allocation for Dual-hop Multi-relay Based Downlink OFDMA Systems

Lin-Hao Dong ； Xu Zhu ； Yu-Fei Jiang ； Yi Huang

《Mobile Computing》 2卷1期 (2013/02) Pp. 1-8

並列摘要

We proposed an optimal asymmetric resource allocation (ARA) scheme for the decode-and-forward (DF) dual-hop multi-relay systems in the downlink, with Orthogonal Frequency-Division Multiple Access (OFDMA) for multiuser transmission. Our work is different in that the time slots for the two hops via each of the relays are designed to be asymmetric, i.e., with K relays in the cell, a total of 2K time slots may be of different durations, which enhances the degree of freedom over the previous work. Also, a destination may be served by multiple relays at the same time to enhance the transmission diversity. Moreover, closed-form results for optimal resource allocation are derived, which require only limited amount of feedback information. Simulation results show that, thanks to the multi-time and multi-relay diversities, the proposed ARA scheme can provide a much better performance than the scheme with symmetric time allocation, as well as the scheme with asymmetric time allocation for a cell composed of independent single-relay sub-systems, especially when the relays are relatively close to the source.

並列關鍵字

Relay ； Resource Allocation ； OFDMA ； Asymmetric Time Allocation ； Multi-relay Diversity ； Multi-user Diversity