Implementation of Turbo decoder using MAX-LOGMAP algorithm in VHDL

Abstract

Design and implementation of a Turbo decoder on FPGA is a challenging task. Various algorithms based on the BCJR algorithm have been proposed to enable the implementation of Turbo decoding in a hardware device. With the advent of FPGAs, the realization of the BCJR algorithm and different simplified versions of BCJR algorithm on hardware is possible. A VHDL implementation of Turbo decoder using the MAX-LOG-MAP algorithm has been discussed in this paper. The target device used for this implementation is Xilinx Virtex-6 FPGA. Simulation and synthesis were carried out using ModelSim SE 6.1 and Xilinx ISE 10.1. BER plots and input and output waveforms for interleaver, deinterleaver, MAX-LOG-MAP decoder and Turbo decoder are also presented.