Generalization Research And Design Of Permutation Mode Orthogonal Frequency Division Multiplexing With Index Modulation

The OFDM-IM system combining Index Modulation(IM)technology and Orthogonal Frequency Division Multiplexing(OFDM)can improve the achievable bit rate and bit error rate(BER)of the system performance.In OFDM systems,IM applications are mainly divided into single-mode systems and multi-mode systems.The single-mode system has high energy efficiency and strong anti-frequency deviation ability,but the improvement of the system's spectrum efficiency is limited.The spectrum efficiency of the multi-mode system has been significantly improved,but the energy efficiency and anti-frequency offset ability of the system are reduced,which will affect the BER performance of the system.Permutation mode index modulation orthogonal frequency division multiplexing(Permutation Mode OFDM with Index Modulation,PM-OFDM-IM)system combines the advantages of a single-mode system and a multi-mode system,so that the spectrum efficiency of the system is better than that of a single-mode system.The system's anti-frequency deviation ability is better than that of multi-mode systems,and its BER performance can achieve better than single-mode and multi-mode systems.However,the spectrum efficiency of this system is very different from that of a multi-mode system,and the design of the transmission structure of the system cannot guarantee a large anti-frequency offset effect.Therefore,this thesis makes in-depth research and improvement on the basis of the PM-OFDM-IM system.The specific research content and results are as follows:1.This thesis proposes a generalized PM-OFDM-IM(Generalized PM-OFDM-IM,GPM-OFDM-IM)system.The system first integrates the index activation bits and index permutation bits of the PM-OFDM-IM system into index bits,and then sets the system activation sub-carrier selection set,and no longer fixes the number of activated sub-carriers of the system sub-blocks,and completes sub-block generalization goal.Generalization operation can not only improve the spectrum efficiency of the system but also enhance the ability of the system to resist frequency deviation.This thesis first compares the spectrum efficiency of the proposed system with other classical systems theoretically,and the result shows that the spectrum efficiency of this system is almost the same as that of the multi-mode system.Then the thesis analyzes the BER performance and anti-frequency offset ability of the system under the wireless channel.Finally,it is proved by simulation that the BER performance of this system under Rayleigh fading channel is better than other classical systems.And the system's anti-frequency offset ability is better than that of multi-mode systems and PM-OFDM-IM systems.2.The GPM-OFDM-IM system uses a variety of different and distinguishable constellation sets to modulate and map traditional information,and the design of high-order constellation sets will have a higher impact on the BER performance of the system.Therefore,this thesis proposes a high-order constellation optimization scheme based on Amplitude Phase Shift Keying(APSK)and a corresponding low-complexity detection algorithm based on Maximum Likelihood(ML).In this scheme,the concentric circles of APSK correspond to different elements in the GPM-OFDM-IM system set,while keeping each activated sub-carrier using the same constellation set.Through simulation verification,the GPM-OFDM-IM system using the new constellation modulation and detection algorithm has better BER performance and can effectively reduce the computational complexity of the system.