A Simple and Effective Testing Method for the Implementation of Turbo Decoders

It is well-known that Turbo codes are very useful in digital communications. However, due to the existence of interleaver/deinterleaver, there is no effective way available to test the correctness of the ´turbo´ algorithms in practical use such as FPGA/DSP implementation, especially in very low bit error rate. In this paper, based on the extractable theoretical bounds for interleaver by-passed systems, a simple but effective testing method is proposed by separating the turbo coder into interleaver/ deinterleaver part and soft-in soft-out (SISO)-iterative decoding part. Our analysis and simulation results for turbo code shows that the proposed method brings no extra cost in implementation and is proved to be practical and effective. In principle, the proposed method can be generalized to almost all turbo or turbo-like systems, in which the theoretical bounds can be extracted in the absence of interleaver/de-interleaver.