On The Design Of Index Modulation Schemes Under MmWave Massive MIMO Deployment

In the fifth-generation wireless communication network,millimeter wave communication is an extremely important communication technology that has received widespread attention.And as a green communication modulation technology with high spectrum efficiency,index modulation has gradually become one of the most promising technologies in 5G wireless communication.The existing index modulation scheme can work well in the microwave scene,but there are still some problems in the use of the millimeter wave scene.In this paper,based on the characteristics of millimeter wave communication and the needs of future communication deployment,the index modulation technology suitable for millimeter wave massive MIMO scenarios is studied.The main content can be summarized as follows:Firstly,a beamspace modulation technology suitable for millimeter wave scenarios is proposed.The millimeter wave frequency band is subject to high propagation path loss and absorption.When the transmission signal uses millimeter wave as the carrier,it is susceptible to interference from external noise,and serious paths Loss limits its coverage distance.Therefore,it is necessary to deploy large-scale antennas at both ends of the transceiver to obtain array gain,and combine beamforming technology to generate high-gain beams in a specific target direction.In the traditional spatial modulation scheme,only a small number of antennas are activated in each communication slot.Therefore,if the traditional spatial modulation scheme is directly applied in the millimeter wave system,the array gain of large-scale antennas cannot be utilized.At the same time,in the microwave frequency band,due to the rich scattering and reflection,when the antenna spacing is greater than half the wavelength,the correlation between different antennas is not significant.However,in the millimeter wave frequency band,the spatial channels are highly correlated.Therefore,this paper considers combining beamforming technology to transmit data information through the index of the beam,and realizes the effective increase of SE without increasing the hardware complexity.At the same time,in order to further improve the system performance,the spreading code index resource is introduced.The introduction of the spreading code index saves the consumption of the physical link,especially the radio frequency link,and can also maintain the good anti-interference and anti-multipath capabilities of the spread spectrum communication technology,which meets the requirements of the current terminal for wireless transmission technology.Secondly,non-orthogonal multiple access scheme with beamspace modulation suitable for3 D MIMO scenarios is proposed.From the perspective of network development trends,especially in the past two years,the development of wireless networks has shown a trend of becoming hotter,with 20% of the area already carrying 60% to 70% of the traffic.The use of 3D beamforming can be more suitable for future system deployment.In combination with non-orthogonal multiple access technology,system capacity can be further improved.In the sparse spread spectrum design,the user's spatial channel is jointly considered,and the spread spectrum pattern is designed according to the correlation of the user channel.In the channel model,the problems of shared paths and inter-beam interference among multiple users have been addressed in a targeted manner,which reduces the interference between users while obtaining diversity gain.In addition,the corresponding beamspace optimization algorithm and low complexity detection algorithm are given.In the beamspace construction,the beamspace is optimized by minimizing the paired error probability,and the proposed low complexity detection algorithm ensures the bit error rate performance and greatly reduces the detection complexity.Thirdly,beamspace index modulation with adaptive activation scheme is studied.Specifically,the beam index modulation scheme suitable for actual communication scenarios is studied,and the traditional equal-probability activation beamspace scheme is improved.In actual communication scenarios,the channel quality of different links is different.When a poor quality link is selected for transmission,its performance loss may not necessarily be compensated by the additional index information carried by the spatial modulation.Therefore,from the perspective of maximizing the system capacity,an optimized activation probability distribution is obtained.Based on this,an effective coding and modulation scheme based on huffman coding is proposed.In order to reduce the complexity of detection,MPA is used for joint detection of index information and data information,and specific factor graph construction and detection algorithm flow are given.The simulation result proves the feasibility of the proposed beamspace modulation scheme.While improving the system capacity,it reduces the bit error rate and solves the performance loss caused by the difference in channel quality of different links.