Research On The Physical Broadcast Channel Information Extraction Of TD-LTE Using FPGA

TD-LTE is one of the main stream technology in the fourth generation of mobile communication.The 3GPP organization put LTE as the system long term evolution technology for the third generation of mobile communication system, and carried out the feasibility study and the standardization work,LTE has get the widest participation and support by equipment manufacturers and operators. MIMO(Multiple Input Multiple Output)and OFDM(Orthogonal Frequency Division Multiplexing) technology are the two key technologies in LTE system.TD-LTE broadcast system follows the traditional design idea of broadcast system, the purpose of broadcast system is to guarantee that UE can normally access resident district and serve for it, and providing needed channel information and idle mobility management when it access to cell network.According to the importance of system information and different transmission modes,it includes the main information block system information and system information block. This paper studies the main information block, which contains information of physical hybrid automatic retransmission indicating channel information, small bandwidth, system frame number as the most basic cell information.In this paper, the physical broadcast channel information extraction of LTE and tail biting convolutional decoding algorithm is studied. On the physical broadcast channel, the sender and the receiver of each process is reasearched, including: cell scrambling and descrambling, rate matching and de-rate matching, tail biting convolutional encoding and decoding, CRC scrambling and descrambling and CRC check, each process is writed for MATLAB codes and simulation experiment is carried out; by using FPGA, the physical broadcast channel extraction is achieved; the Viterbi algorithm is studied, an improved tail biting convolutional decoding algorithm is proposed — — decoding algorithm combined with positive reverse.The sender and the receiver of the physical broadcast channel co-simulation on MATLAB, by comparing the sender and the receiver, it verify the correctness of the data;the receiver of each process is realized by FPGA programming, by comparingthe datas between the MATLAB’s with the FPGA’s, it verifies the correctness, and the FPGA programming can be used in LTE system; Meanwhile, the improved algorithm and existing algorithms were simulated and compared on MATLAB, the improved algorithm can reduce the error rate, it is applicable to LTE system for tail biting convolutional decoding.