Subcarrier and power allocation for OFDMA-based regenerative multi-hop links

Mesh network, with its many advantages, is one of the most promising topologies in the future distributed wireless network. The system performance can be unproved by optimally allocating the overall power and bandwidth to the transmitter and the relays. This paper focuses on the subcarrier and power allocation in orthogonal frequency division multiple access (OFDMA) based regenerative mesh network. Three sub-optimal allocation strategies are presented in this paper to maximize the end-to-end capacity in multi-hop link. The first one, "reference strategy (RS)", is a discrete version of the algorithm proposed in M. Dohler (2004). Another strategy named "uniform power strategy (UPS)" allocates uniform power to each hop while optimally assigns the number of subcarriers. In the last strategy, "uniform ratio strategy (URS)", each hop is identical in terms of power-to-subcarrier ratio. Numerical simulation demonstrates that URS and RS perform better than UPS in asymmetric case, where the average channel gain of each hop is different. With the increase of subcarrier number, end-to-end capacity of URS becomes larger than that of RS. However, in symmetric case, the UPS outperforms URS and the RS at small subcarrier number.