Complexity reduction of turbo decoding

This paper addresses two complexity reduction techniques for turbo decoding. The first is turbo-CRC encoding where CRC is incorporated into the turbo decoding iteration processes to reduce the average number of iterations needed. Simulations show that the W-CDMA reverse link suffers no performance degradation even if the average number of iterations is reduced by more than 75% at BER=10/sup -6/ under frequency selective Rayleigh fading. The second is a new low-complexity turbo internal interleaver called the prime interleaver. Turbo coding with the proposed interleaver can generate codewords having good Hamming weight for a wide range of interleaving lengths (257-8192 bits).