Research On Index Modulation And Phase Shift Design Assisted By Intelligent Reflecting Surface

Intelligent Reflecting Surface(IRS)is a hypersurface composed of a large number of lowcost,low-power,and adjustable reflective components.IRS can programmatically control the reflective phase shift through a controller and has been considered a key technology in the sixth generation wireless communication system.In addition,Index Modulation(IM)technology can transmit information through the switching state of resources,improving the information transmission rate and energy efficiency of the system.Integrating IRS technology and IM technology for research is expected to improve the overall performance of the system.Therefore,this article carried out the following work:(1)This article proposes an index modulation and phase shift design scheme based on a single IRS.This article focuses on a single IRS assisted multi input single output communication system,when the transmitter of the system adopts Space Shift Keying(SSK)modulation,the phase shift is optimized to maximize the Euclidean distance between different transmission vectors,and a phase shift design algorithm based on cosine similarity is proposed.Compared with the phase shift design algorithm that maximizes the Signal to Noise Ratio(SNR)of the receiver,the phase shift design algorithm based on cosine similarity enables the system to have better Bit Error Rate(BER)performance.In order to further improve the BER performance and information transmission rate of communication systems,this paper extends the phase shift design algorithm based on cosine similarity to the transmission end SSK combined with IRS group index modulation system and the transmission end SSK combined with IRS reflection phase shift modulation system.When indexing and modulating the IRS group,the reflection phase shift grouping is designed,with each reflection unit group sharing a common phase shift.When using reflection phase shift modulation in IRS,the reflection phase shift is first optimized based on cosine similarity,and then phase shift modulation is performed.The simulation results show that the index modulation and phase shift design scheme based on a single IRS proposed in this paper not only improves the system information transmission rate,but also achieves good BER performance.(2)This article proposes an index modulation and phase shift design scheme based on dual IRS.Among them,the first IRS serves as the transmitter to transmit the signal,and the second IRS is used to reflect the signal.Dual IRS can provide greater index modulation freedom and more reliable link gain.To enhance the received signal strength,the reflection phase shift is designed with the goal of maximizing the SNR of the receiving end.Firstly,this article proposes a dual IRS Joint Group Index Modulation and Reflection Phase Modulation(DIRS-GIM-RPM)scheme.In the DIRS-GIM-RPM scheme,the first IRS performs reflection phase shift modulation,the second IRS performs group index modulation,and the receiver performs spatial modulation.The phase shift of the first IRS is optimized for channel gain maximization before phase shift modulation.The second IRS shares a common phase shift for each reflection unit group and is designed using channel gain maximization.Secondly,this article proposes a Double IRS Aided Information Distributed Receipt(DIRS-IDR)scheme.In the DIRS-IDR scheme,there are two receivers receiving information in a distributed manner.The first IRS performs reflection phase shift modulation,and the second IRS is divided into two groups.The reflection phase shift is optimized for both receivers.The simulation results show that the dual IRS scheme proposed in this paper has good BER performance.