Joint Resource Allocation in OFDMA/CDMA Spectrum Refarming System

Spectrum refarming (SR) is drawing a lot of attention nowadays for its capability to alleviate the spectrum scarcity problem by allowing different generations of cellular networks to operate in the same radio spectrum. In this paper, we propose a joint resource allocation scheme for the uplink OFDMA/CDMA SR system, by exploiting the tradeoff of the OFDMA throughput over the CDMA receive power. By investigating the convexity of the OFDMA throughput over the CDMA receive power, an algorithm, performed by the OFDMA system, is proposed to jointly optimize the OFDMA resource allocation and the CDMA receive power. Due to the existing CDMA uplink power control, when the OFDMA users transmit with the optimal allocated resource, the CDMA system will adjust its user transmission power to make the receive power be the optimal value, for guaranteeing the target signal-to-interference-plus-noise ratio. Simulation results are provided to verify the proposed scheme and algorithm.