Research On Spatial Modulation Technology In High-speed Railway Communications

Spatial modulation technology(SM),as a new type of multiple-input multiple-output(MIMO)communication technology,which has become a research hotspot in the field of wireless communications.In addition to transmitting the information bits through traditional modulation,it can also transmit the carried information bits through the activated antenna index at different positions.On the other hand,due to the unique communication scenarios of high-speed railways(HSR),to improve the performance of existing HSR communication systems,one approach is to introduce SM technology into the HSR communication system.This application of SM technology to HSR communication is a new research hotspot in academia,which can greatly improve the overall performance of HSR communication systems.This paper delves into the spatial modulation and related technical theories in HSR communication scenarios.In this thesis,the basic theoretical knowledge of SM in HSR scenario is firstly elaborated,and proposes a generalized SM scheme for multiple antenna groups and an enhanced SM scheme for multiple antenna groups in HSR communication scenarios.One of which is based on generalized SM and the other enhanced SM,even if these are two completely different communication schemes but both different approaches and equally satisfactory results.The GSM technology of multi-antenna groups in high-speed rail communication scenarios is a combination of antenna groups and GSM technology,and this idea can significantly increase the capacity of high-speed rail communication systems without affecting other system performance.The enhanced SM for multi-antenna groups in high-speed rail communication scenarios is to combine the main constellation and auxiliary constellation modulation technology with the multi-antenna groups,and this concept can increase the number of antenna and modulation mapping combinations that significantly improve the overall performance of the high-speed rail communication system capacity index.In short,these two technical solutions can solve the problem of the information rate bottleneck of the high-speed rail communication system.The simulation results show that the two proposed high-speed rail communication SM technology can significantly improve the performance indicators,such as the information transmission rate of the existing communication system and have good robustness.Secondly,based on the characteristics of the traditional dual-symbol SM and single-symbol SM schemes and combining the special scenarios of HSR,we propose a novel three-symbol SM scheme for high-speed rail communications.The basic principle of the three-symbol SM for high-speed rail communication is to transmit a single modulation symbol or two modulation symbols with optimal rotation angles to transmit data at different time slots,which can not only increase the capacity of the high-speed rail communication system,but also enhance the anti-interference ability due to the use of optimal angle rotation.Therefore,the proposed technical solutions not only improve the information transmission rate,but also improves the performance of receiver complexity relate to other specific SM technologies,and which achieve good compromise in overall performance.The simulation results further show that the proposed three-symbol SM scheme can be well applied in high-speed rail communication scenarios,and can improve the shortcomings of existing high-speed rail communication technologies,that is a very promising high-speed rail communication technology.