Polarization Mode Dispersion Tolerant Subcarrier-Power Allocation for Improving the Power Amplifier Energy Efficiency of Joint Polarization-Amplitude-Phase Modulation

A Polarization Mode Dispersion Tolerant Subcarrier-power Allocation (PMDTSA) scheme is proposed to improve the Power Amplifier (PA) energy efficiency. The proposed scheme is applied in the multiuser downlink system based on Joint Polarization-Amplitude-Phase Modulation (JPAPM). Dut to the wireless channel´s polarization mode dispersion effect, the polarization based impairment to JPAPM on each subcarrier will be diverse. Through the optimal subcarrier-power allocation, such diversity can be utilized to make PA energy efficiency optimal under the constraint of each user terminal´s data rate demand. To reduce the allocation´s computationally complexity, the PMDTSA scheme performs the subcarrier allocation and power allocation separately. Firstly, assuming the equal power distribution, the subcarrier is allocated through Particle Swarm Optimization (PSO); then based the obtained subcarrier allocation method, a two-step allocation algorithm is presented to distribute the PA input power on each subcarrier. Through numerical calculation, the optimal parameters setting of PSO is examined. Our results show that the proposed PMDTSA scheme is able to achieve significant improvement in PA energy efficiency.