Performance Of Index Modulation Wireless Energy Harvesting System

In this paper,the performance analysis and scheme design are carried out under the cooperative relay system,aiming at addressing the problems of low spectral efficiency and the impact of spatial correlation on the bit error rate in an index modulation（IM）Simultaneous wireless information and power transfer（SWIPT）system,in order to optimize the system transmission efficiency,reduce the bit error rate,as well as reduce the energy consumption.The research content can be divided into the following two aspects:Firstly,in order to improve the efficiency in information transmission of the SM-SWIPT cooperative system,a SWIPT system based on generalized spatial modulation-media based modulation（GSM-MBM）is proposed.Specifically,the system transmission rate,the average pairwise error probability（APEP）,and energy consumption gain are derived and the accuracy of the analytical derivations is verified by Monte Carlo simulations.The results show that,under the same transmission rate,compared with the single input multiple output-media based modulation（SIMO-MBM-SWIPT）system,the proposed GSM-MBM-SWIPT enhances the BER by about4～5dB at 10^-4 BER;Compared with the media modulation-media based modulation（SM-MBM-SWIPT）system,the SNR gain of the GSM-MBM-SWIPT system is about1dB at 10^-4 BER.Compared with SM-SWIPT system,although the GSM-MBM-SWIPT system is degraded by about 1～2dB at 10^-4 BER,the required number of transmit antennas is largely reduced,leading to apparent decreasing of the hardware complexity and implementation cost.In terms of energy consumption gain,the GSM-MBM-SWIPT system achieves an energy consumption gain of 1.7 dB.Secondly,in order to overcome the influence of spatial correlation in the SM-SWIPT system,a phase rotation precoding spatial modulation（PSM）-SWIPT cooperative system is proposed.The average bit-error probability（ABEP）upper bound is derived and it matches well with the Monte Carlo simulation results.The influence of the parameters,such as the power-splitting factor and transmit correlation coefficient,on system performance is studied.The numerical results indicate that PSM-SWIPT system enhances the BER by about 5dB at 10^-4 BER.The numerical results also indicate that the proposed PSM-SWIPT system can obtain better ABEP performance than that of space shift keying-SWIPT and multiple-input-multiple-output-SWIPT systems under the same spectral efficiency.In summary,performance of index modulation wireless energy harvesting system proposed in this paper not only improves the spectral efficiency,but also improves the energy efficiency,providing a theoretical foundation for the practical application of 6G communication systems.