Research On Novel Adaptive Index Modulation Techniques For Wireless Communications

As a new type of low-complexity multi-antenna technology,index modulation uses antenna index or subcarrier index as digital modulation methods.Compared with other multi-antenna technology,the advantages of space index modulation are(1)the system has higher spectrum efficiency and low detection complexity;(2)the system has low Radio Frequency(RF)cost.However,the bit error ratio(BER)performance of the space index modulation is highly dependent on the channel.In order to adapt to the changes of the instantaneous channel and improve the robustness of index modulation system,we can combine the space index modulation with the link adaptive techniques for achieving further performance gains.From the point of view of complexity optimization and BER performance optimization,we propose a series of power allocation aided novel space index modulation systems.Meanwhile,we propose some new space index spatial modulation technologies for high frequency communication system.The main work schedule of this thesis is as follows:Chapter 1 introduced the research background and existing contributions of the new space index modulation.Chapter 2 introduced the conventional space index modulation-spatial modulation system model and two new space index modulation system models,including receive spatial modulation and enhanced spatial modulation.Then,three performance analysis methods have been introduced.Chapter 3 studied the combination of the adaptive techniques and the new space index modulation.Based on the minimum Euclidian distance maximization criterion,a power allocation aided receive spatial modulation(PA-RSM)optimization model with average total power constraint was proposed,and the optimal closed-form solution of the model with specific parameters was given.To obtain a universal solution to the optimization problem,an iterative method,which jointly considered the spatial symbols and traditional modulation symbols of the PA-RSM system,was proposed.In order to further reduce the computational complexity,an augmented Lagrange multiplier method that only considered the spatial symbols was proposed.This algorithm was regarded as a trade-off between complexity and BER performance.Since each transmit antenna was equipped with its own power amplifier in the practice system and was limited individually by the power of the amplifiers,PA-RSM optimization model with per-antenna power constraint was proposed.Compared with the conventional RSM without power allocation,the proposed PA-RSM with two different power constraints had significant BER performance gain.Chapter 4 proposed some new space index modulation technologies for high frequency communication system.In millimeter wave communication,an analog beamforming aided RSM(AB-RSM)scheme was proposed to reduce the RF cost.This scheme effectively reduced the hardware cost and computational complexity without losing BER performance.In land mobile satellite communication system,based on polarized antenna technology,a new multi-domain joint index modulation technology,called polarized space modulation(PMod-SM),was proposed,which can avoid the polarization interference between antennas in multi-satellite communication and ensure the BER performance.Chapter 5 summarized the full thesis,and given a prospect for the future research.