FPGA Based Implementation of MSOVA for CDMA2000 Turbo Decoder

Abstract

Soft output Viterbi algorithm (SOVA) and max-log-maximum a posteriori (Max-Log-MAP) are used for turbo codes decoding. SOVA is considered a simple way of implementation with higher throughput in comparison to the Max-Log-MAP, while the later is still superior from decoding performance point of view. A modified SOVA (MSOVA) was theoretically proven to be equivalent to Max-Log-MAP. In this paper a HW implementation for CDMA2000 turbo decoder using MSOVA is presented. This implementation is based on the MSOVA, using Xilinx Virtex 2 pro FPGA. The implementation was shown to have higher throughput and lower latency than a commercial decoder