Turbo decoder implementation

Abstract

Recently, turbo code has gathered much attention for its outstanding performance. However, its complexity and decoding latency are severe drawbacks. Turbo code has been adopted in the 3GPP specification as one of the channel coding schemes. To implement a turbo decoder compliant with the 3GPP specification, the author adopted the sliding window method and devised a way to simplify the E-function of the MAP algorithm. This paper covers the optimum sliding window size and piecewise-linear E-function. In addition, implementing a scheme using the sliding window algorithm is covered. This focuses on implementing an interleaver and deinterleaver. The turbo decoder described is designed according to the 3GPP specification, and every simulation was done under AWGN.