Resource Allocation in Multi-Hop OFDMA Wireless Backhaul Networks With Cooperative Relaying

An optimal resource allocation strategy for OFDMA multi-hop wireless backhaul networks is considered. A cross-layer optimization problem is formulated that maximizes the balanced end-to-end throughput under the routing and the PHY/MAC constraints. A dual method is employed to solve the problem efficiently and optimally by decoupling it into different layers as well as into different OFDM tones. A cooperative relaying technique is incorporated into the framework to improve the performance. Mutual interference between the links is explicitly modeled to allow maximal spatial reuse of the spectral resources, and half-duplex operation of the radios is assumed. The numerical results exhibit how the bottleneck phenomenon typical in multi-hop backhaul networks can be alleviated by the proposed techniques to yield significant improvement in the throughput.