Title :
Radio Resource Allocation for Collaborative OFDMA Relay Networks with Imperfect Channel State Information
Author :
Zheng Chang ; Ristaniemi, T. ; Zhisheng Niu
Author_Institution :
Dept. of Math. Inf. Technol., Univ. of Jyvakyla, Jyvaskyla, Finland
Abstract :
This paper addresses the resource allocation problem in collaborative relay-assisted OFDMA networks. Recent works on the subject usually ignored either the selection of relays, asymmetry of the source-to-relay and relay-to-destination links or the imperfections of channel state information. In this article we take into account all these together and our focus is two-fold. Firstly, we consider the problem of asymmetric radio resource allocation, where the objective is to maximize the system throughput of the source-to-destination link under various constraints. In particular, we consider optimization of the set of collaborative relays and link asymmetries together with subcarrier and power allocation. Using a dual approach, we solve each sub-problem in an asymptotically optimal and alternating manner. Secondly, we pay attention to the effects of imperfections in the channel-state information needed in resource allocation decisions. We derive theoretical expressions for the solutions and illustrate them through simulations. The results validate clearly the additional performance gains through an asymmetric cooperative scheme compared to the other recently proposed resource allocation schemes.
Keywords :
OFDM modulation; frequency division multiple access; relay networks (telecommunication); resource allocation; OFDMA; imperfect channel state information; power allocation; radio resource allocation; relay networks; source-to-destination link; Channel estimation; Collaboration; Optimization; Receivers; Relays; Resource management; Throughput; OFDMA; cooperative communications; imperfect CSI; power allocation; relay selection; subcarrier allocation;
Journal_Title :
Wireless Communications, IEEE Transactions on
DOI :
10.1109/TWC.2014.040714.131695