Research On Power Division Multiplexing Technology In Mobile Communication

In the course of the development of mobile communication system,the change of system standards and mainstream technologies are closely related to the change of people's demand for communication services,and the booming development of mobile internet and Internet of Things put forward the high demand of high spectrum efficiency,large-scale device access and low latency for 5G.The different orthogonal multi-access technologies applied in the previous generations of mobile communication system have been unable to meet the development of 5G.Therefore,it is necessary to study new resource reuse and multiple access protocols to meet the needs of future communications development.In 5G,the NOMA was proposed,and it has gained wide attention from industry and academia because it can more fully utilize the power domain of communication resources.The NOMA allocates different powers to different access users according to the channel state information,which enables the communication system to simultaneously serve multiple independent information streams from different users.Despite the rapid development of the NOMA protocol,the resource reuse technology that supports its work at the physical layer has not been fully studied,resulting in the existing NOMA-based communication systems still using traditional TDM and FDM.Because these traditional multiplexing technologies cannot fully utilize the power domain,the existing NOMAbased system is not efficient.In order to solve these problems,this thesis extends the power distribution technology in the NOMA to the physical layer,and studies new PDM.PDM divides the transmission power into multiple power segments,similar to the time slots in TDM or the frequency bands in FDM,and each power segment is used to transmit a user's information flow.Therefore,compared with TDM and FDM,PDM can better support the NOMA and improve the system performance.In this thesis,the PDM of integrated multi-antenna technology and OFDM is studied.The specific research results of this thesis are as follows.Firstly,Since the existing PDM is carried out under a single antenna system,the system capacity,spectrum utilization rate and other aspects have not been able to meet the target requirements,and can't resist the decline of multiple paths.Therefore,this thesis introduces the multi-antenna technology in PDM,and studies the PDM integrated the multi-antenna technology.According to the multi-antenna system,it can be divided into the following three aspects.The PDM in MISO system.This thesis puts forward the specific scheme of PDM in the MISO system.Besides,under the optimization target of ensuring the maximum transmission rate of the system,the optimization algorithm is proposed for the power distribution of multiple data streams between multiple antennas of the transmitter,which improves the accuracy of the transmission signal of the system.The PDM in SIMO system.This thesis puts forward the specific scheme of PDM in the SIMO system.Besides,in order to maximize the receiving diversity effect of the system,the optimization algorithm is proposed for the post-processing process by using the information of each channel to ensure the performance of the system.The PDM in MIMO system.This thesis puts forward the specific scheme of PDM in the MIMO system.Besides,in order to ensure the gain of the MIMO system,the power control and combining algorithms in this system are optimized,and the variable ? in the power control algorithm is discussed to ensure the accuracy of the system.Further,the MATLAB platform was used to simulate the above research results,and the PDM scheme and optimization algorithm under different multi-antenna systems were verified.Secondly,Since the existing PDM schemes are all implemented in the form of a single carrier,they cannot effectively overcome frequency selective fading in practical applications.Therefore,this thesis further studies the PDM scheme based on OFDM under the multi-antenna system.The introduction of OFDM will bring synchronization problems to this system,causing Inter-Carrier Interference and Inter-Symbol Interference,which will affect the performance of the system.In order to solve this problem,this thesis designs the auxiliary information such as preamble and pilot of this system,and uses the auxiliary information to design of synchronization algorithm and channel estimation algorithm.Further,the simulation on the MATLAB platform verifies the feasibility of the proposed scheme and the correctness of the algorithm.