Resource Allocation in OFDM based Multihop Wireless Networks

Abstract

OFDM modulation and multihop transmission are two important techniques for future wireless networks. This paper discusses the adaptive subcarrier and power allocation in OFDM based multihop networks. Both OFDM-TDMA and OFDM-FDMA access methods are considered. For OFDM-TDMA based multihop networks, a power allocation algorithm is proposed to maximize the end-to-end capacity for the constraint of the overall transmit power of all hops. For OFDM-FDMA based multihop networks, a joint subcarrier and power allocation algorithm is proposed. The performances of the proposed algorithms are evaluated, in both symmetric case (each hop has same average channel gain) and asymmetric case (the hops have different average channel gain). The results show that the OFDM-FDMA access method achieves a higher end-to-end capacity than the OFDM-TDMA access method, and the proposed adaptive resource allocation algorithms perform better than the fixed resource allocation strategy, in both cases.