Research On Multi-Domain United Modulation Technologies For Wireless Communications

2019 is the year one of the era of the fifth generation(5G)mobile communication and the three main applications of 5G,namely the enhanced Mobile Broadband(eMBB),Ultra Reliable Low Latency Communications(URLLC),and massive Machine-Type Communications(mMTC),have put forward high demands for the current wireless communication technology and the development of new wireless transmission technology is urgently needed.Motivated by the shortcomings of the key technology of the fourth generation(4G)mobile communication—Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing(MIMO-OFDM),this thesis seeks to study novel MIMO-OFDM transmission schemes based on the index modulation(IM),and use the Universal Software Radio Peripheral(USRP)to build wireless testbed systems so as to test the performance of the proposed schemes over the realistic propagation environment.The specific contributions of this thesis are listed as follows:First,this thesis provides a comprehensive review concerning the development and research status of the index modulation from the perspective of both theoretical approach and experimental approach.Secondly,this thesis introduces some novel SM based OFDM and OFDM-IM based MIMO-OFDM transmission schemes,and makes performance comparisons between these two novel MIMO-OFDM schemes over the Long-Term Evolution(LTE)Extended Vehicular A(EVA)channel model.Then,the thesis proposes a novel Enhanced SM based OFDM(ESM-OFDM)transmission scheme,and compares its performance with the SM based OFDM(SMOFDM)by using Monte Carlo simulations.Moreover,the wireless testbed systems of the ESM-OFDM&SM-OFDM are built based on the National Instrument(NI)USRP platform and the performance superiority of the proposed ESM-OFDM scheme is verified by the experimental results over the real wireless channels.After that,the thesis introduces the link adaptation(LA)technologies to the ESM-OFDM and proposes a novel power allocation aided ESM-OFDM(PA-ESMOFDM),which is capable of jointly utilizing the asymmetry of the ESM signal constellation of the asymmetry of the MIMO antennas' power to further improve the system performance,Moreover,this thesis derives the closed-form solution of the optimal PA matrix based on the proposed optimization method.Furthermore,the wireless hardware testbed systems are built for both the proposed PA-aided ESM-OFDM and the conventional equal-gain based ESM-OFDM,in order to carry out further comparisons.Finally,both of the Monte Carlo simulations and experimental results show the performance superiority of the proposed PA-aided scheme.Finally,the main contents of the thesis are summarized,and the possible future research directions are discussed.