The Design And Implementation Of TD-SCDMA Downlink Matched Filter And Pre-synchronized

TD-SCDMA is our country’s independent development of Third Generation Mobile Communication System, with independent rights of intellectual property. It uses a series of world’s leading technologies like synchronous CDMA、smart antennas,joint detection,relay switching,low chip rate and software radio etc.In TD-SCDMA system, SCDMA means synchronous CDMA, We must solve downlink matched filtering and timing synchronization problems. Traditional correlation algorithm is completed by correlation function in software, that algorithms not only require a long time and high power consumption, but also high complexity in implementation. In order to achieve low-cost TD-SCDMA equipments, like repeater etc, needing to develop a low-complexity timing synchronization algorithm. In view of these considerations, we research low-complexity timing synchronization problems, and we present a new non-coherent algorithm based on power ratio detection.In this paper, first,we study the structure of TD-SCDMA physical signal, and we extract the special structure of TD-SCDMA, then design pre-synchronization algorithm of TD-SCDMA, this algorithm combined with traditional matched filtering, making full use of redundancy provided by over-sampling after matched filtering, to achieve matched filtering and synchronization with a low price. We verify our algorithm by computer simulations, and the results show a good and robust performance in a wide range of signal-to-noise ratios. Finally, we use hardware description language Verilog HDL, to implement algorithm in FPGA. The results show that the algorithm is feasible.