Viterbi Algorithm: Analysis And Implement

Viterbi algorithm is a maximum_likehood algorithm for convolutional codes, its complexity will increases exponentially with the constraint_length, and it is also an optimal state estimation algorithm for the finite state process. There are two popular ways to implement the viterbi decoder: DSP (digital signal processor) and ASIC (application special integrated circuit). In the recent years, with the improvement in LSI(Large Scale Integration) technology, the hardware implementation has become more and more favorable.In this paper, the theory and the application of Viterbi algorithm are expatiated. And after thorough studying the operation process, configuration and optimizing ways of Viterbi algorithm, a new dynamic management method of path metric memory is presented to improve the performance. It was shown that the decoder's complexity can be decreased effectively with reasonable decoding speed, and it can be implemented in FPGA easily.The major work is as following:The state estimation of HMM process by viterbi algorithm was studied in detail.The optimizing ways in operational process, memory arrangement and structural design of decoder was discussed deeply when it was implemented in hardware.A viterbi decoder for (2, 1, 6) convolutional code was designed with VHDL in xilinx ISE5.2i, and it had been simulated by modelsim.