A new adaptive strategy for turbo decoder with prior statistical knowledge of extrinsic information over AWGN and fading channels

摘要

In this paper, a new adaptive strategy for turbo decoder with prior statistical knowledge of extrinsic information is proposed. In this scheme, a test pseudorandom bits block with known distribution patterns of 1s and 0s by both the transmitter and receiver are send to the receiver when the channel status changes and is detected by the receiver. The turbo decoder computes the conditional probabilities mass functions of the extrinsic information for both arms at each iterative decoding by using the test block. These updated probabilities mass functions are kept in the turbo decoder to replace the conventional Gaussian assumptions for iterative decoding of information bits block over additive white Gaussian noise and various fading channels. The simulation results show that such a novel iterative turbo decoding has considerable performance gains over the conventional ones under the same channel conditions.