Research On Hybrid Prefix-Based New Multi-Carrier Transmission Technology

With booming demand of the pluralistic information,there are great potential development value and vigorous vitality in wireless mobile communication.Orthogonal frequency division multiplexing(OFDM)has become the most dominant technology in wireless communication due to its ability to resist frequency selective fading effectively.Moreover,it has been adopted as the downlink physical layer multiple access technique in the fourth-generation mobile communication system(4G)and will be used in 5G subsequently.However,with the shortage of communication resources caused by high-speed transmission demand,how to improve spectrum efficiency become the core issue in the future mobile communication.Specifically,the cyclic prefix in OFDM system is effective means to counter multipath interference,which can not only ensure the system performance,but also lead to severe waste of spectrum resources.This phenomenon is particularly serious in complex channel environments with high propagation delay.Hence,a new multi-carrier transmission technology is proposed in order to reduce cyclic prefix redundancy in this paper,which can improve the spectrum utilization of the system while ensuring transmission reliability.For the new multi-carrier transmission technology,the following researches are carried out in this paper:The first chapter introduces the basic principles of OFDM system and MIMO system respectively.Meanwhile the traditional multicarrier technologies to reduce cyclic prefix redundancy are presented.In the second chapter,the influence of cyclic prefix on the performance of OFDM system is analyzed.Subsequently a new hybrid prefix multicarrier technology is proposed to improve the spectral efficiency,and its theoretical and actual performances in SNR and BER are analyzed and simulated under the single antenna environment.Finally,optimum power allocation is used to further improve the BER performance of the new transmission technology.The third chapter realizes the theoretical analysis and simulation verification of the SNR and BER performance of the new multi-carrier transmission technology under the multiple antenna environment to expound the performance difference compared with traditional OFDM system.Simultaneously,power allocation algorithm is proposed to improve the transmission performance of the new technology in multi-antenna systems.The fourth chapter focuses on avoiding inter-symbol interference introduced by special symbol structure,and proposes an enhanced receiver with signal recovery capability which improve the performance effectively at the expense of complexity to update the new multicarrier technology.In addition,the new system structures for NCassisted and STC-assisted hybrid prefix multicarrier technology are proposed to be suitable for different multi-carrier designs.The last chapter is a summary of the full text which describes the contribution of this article and possible future research directions.