Channel allocation for a 2-hop OFDMA virtual cellular network

A multi-hop virtual cellular network (VCN) was proposed for future broadband mobile communication systems. Orthogonal frequency division multiple access (OFDMA) can be used as the multi-hop wireless access technique. However, since the number of available subcarriers is limited, the same subcarrier must be reused in different multi-hop links and therefore, co-channel interference limits the performance of multi-hop OFDMA VCN. Using OFDMA, the channel is composed of a block of subcarriers. OFDMA VCN requires an adaptive channel allocation to minimize the co-channel interference. The link performance can be improved by allocating a block of subcarriers with a good propagation channel condition. In this paper, we propose a distributed channel allocation scheme based on the maximization of the signal-to-interference plus noise power ratio (SINR) of each multi-hop link. Since the channel allocation is performed at each link, central port does not need to collect the SINR information of all multi-hop links. We numerically evaluate the downlink channel capacity of 2-hop OFDMA VCN and compare it with VCN using 2-hop direct sequence code division multiple access (DS-CDMA).