Energy efficiency resource allocation research based on MIMO-OFDM for cognitive radio systems

摘要

Conventional researches of cognitive radio (CR) systems mainly focus on improving system throughput or spectrum efficiency. Since nowadays energy consumption of wireless communication is increasing, this paper intends to improve the energy efficiency of CR system based on multiple input multiple output-orthogonal frequency division multiplexing (MIMO-OFDM), and the problem is studied under the constrain of total power, the interference power, and the rate. Since the power allocation is non-convex problem, in order to find the optimal power allocation at each subcarrier of each antenna, we proposed a novel method based on traditional water-filling power allocation algorithm. Compared with conventional algorithm, numerical results confirmed the advantage of the proposed algorithm. Comparison between energy-efficient power allocation and the spectrum-efficient power allocation in MIMO-OFDM-based CR systems is given under different constraints via numerical simulations as well.