Research And Implementation Of Ultra-high Speed Transmission Of Millimeter Wave MIMO Communication

The rapid development of wireless network technology has prompted the emergence of more new services,which require lower latency and higher throughput.Enhanced mobile broadband(e MBB),ultra reliable and low latency communication(URLLC)and massive machine type communications(m MTC)are typical scenarios in the fifth generation mobile communication system(5G),where millimeter wave(mm Wave)plays an important role.There are already lots of research on mm Wave communications from companies,vendors and universities.This thesis aims to research on the key technologies of ultra-high-speed mm Wave MIMO system.Referring to 802.11 aj and 5G New Radio(NR)physical layer standards,a mm Wave MIMO prototype for ultra-high-definition(UHD)video transmission is developed based on the field programmable gate array(FPGA).The main work of this thesis is as follows:Firstly,an intelligent beam width optimization(BWO)algorithm is proposed to suppress beam drift effect in the mm Wave communication system.The adaptive beam width modulation is formulated as a context-based online random selection optimization,where each option corresponds to a different beam width in a multi-resolution code book.At the initial step of each time unit,the context of the communication environment is constructed and the neural network is used to obtain the required nonlinear features,and then the optimal beam width used for data transmission is determined by the Bayes linear decision model.The BWO algorithm can sense the rate of environmental changes,and adaptively adjust beam width to acquire the higher signal-to-noise ratio(SNR).Then,the physical layer standards of mm Wave wireless communication are investigated,including the physical layer parameters,frame structure and baseband processing flows of the 802.11 aj and 5G NR.The features and resources of the hardware and software are introduced in detail,and the high-speed control scheme of the phased array antenna is given.Based on this platform,the mm Wave 2 × 2 MIMO prototype is designed.Next,the baseband processing flows of the mm Wave MIMO prototype are analyzed,the solutions of the corresponding modules are given,and the specific implementation of some key modules is introduced in detail.Considering the high sampling rate and poor coarse synchronization in the mm Wave system,a fine synchronization scheme based on short training fields is designed to achieve symbol level synchronization.Considering the cyclic shift in the MIMO system,a ping-pong operation on the memory is designed to achieve any degree of cyclic shift.In order to reduce the bit error rate(BER)of the prototype and support higher-order modulation,the channel coding and decoding module,whose throughput can support up to 6.4 Gbps is designed and completed.Considering the processing characteristics of FPGA,the rate matching is transformed into the data padding and distinguishing between valid data and padding data by the specified identifiers,and then hardware implementation is given in detail.Then,the corresponding solutions are given for the difficulties of communication between FPGAs in the prototype,including high-speed data transmission and high-precision synchronization.Aiming at the interface rate bottleneck,a high-speed Serdes channel based on the Aurora protocol is implemented,with each channel supporting a payload rate up to 11 Gbps.Aiming at the synchronization between FPGAs,a master-slave synchronization scheme is designed to ensure the two PFGAs responsible for baseband processing synchronized under the high rate clock.Finally,ultra-high-definition video transmission can be achieved,based on the mm Wave 2×2 MIMO prototype.The solution to video transmission is designed,including the server pushing data stream,optical fiber communication,and the implementation of the Ethernet protocol stack in the FPGA,which can support up to 10 Gbps.To address the overflow of data buffers in the FPGA in the case of data rate up to 1 Gbps,the dynamic random memory is packaged into a queue structure to receive video data.To address the destruction of the RTP packet boundary,a boundary protection mechanism that video data encapsulation and filtering is designed.The clear play of the 380 Mbps live stream and 1.5 Gbps file stream verifies the high bandwidth and low latency of the millimeter wave 2 × 2MIMO system.