Development Of LTE-A Third-party Non-cooperative Target Capture And Recognition System

The LTE-A(Long Term Evolution-Advanced)system has become the most popular current mobile communication technology,and mobile phones have become the basic communication tools of humans,and mobile phones have become one of the main communication tools of criminals,too.In recent years,China's anti-terrorism stabilization situation has become increasingly severe,and the security pressures of major events have become increasingly prominent.The state has invested more in the construction of antiterrorism and stability measures.The demand for accurate acquisition equipment for LTEAdvanced mobile terminal targets is urgent.Therefore,it is necessary to realize the target capture identification system development,capture and identify the identity characteristics of sensitive users in the LTE-A network.In this thesis,based on the "LTE-A downlink signal receiving and processing FPGA and DSP software" project,it finally needs to monitor those specific users in the cell to complete target identity feature recognition.The project utilizes FPGA(Field Programmable Gate Array)parallel processing and high DSP(Digital Signal Processor)operation speed.The DSP is used as the control core of the whole system,The FPGA chip performs downlink cell search and synchronization,signal detection,and reception processing of each physical channel under the control of the DSP,and it transmits the data carried by the channel to the DSP,then the DSP parses the message.This thesis proposes a signal detection algorithm with low complexity to optimize selection of the antenna index set.The results show that the proposed algorithm can obtain a similar bit error rate performance as the maximum likelihood(ML)detection algorithm with more than 90% reduction of complexity.This thesis designs a cell search PSS capture processing comparison decision algorithm.The synchronization point location and the intra-group ID can be accurately obtained,the efficiency of cell search is greatly improved.These two algorithm significantly improves the message resolution rate of the downlink physical channel.The function of cell search,signal detection and downlink physical channel receiving and processing in the target acquisition and identification system is simulated and verified on the board under 20 M system bandwidth and 122.88 MHz system operating clock.Parsing captured system messages,paging messages,and random access messages,the final result shows that the MIB message capture rate is close to 100%,the SI message capture rate is 98%,the SIB message capture rate is 92%,the Paging message capture rate is 93%,and the MSG4 message capture rate is 78%.In summary,the target capture and recognition system has successfully completed the task of capturing and identifying tasks.This thesis has carried out a comprehensive evaluation of the timing resources and system resources.The chip resource consumption rate of the FPGA is 23.6%,it provides the possibility for the expansion of subsequent projects.