A CRC-Aided Hybrid Decoding Algorithm for Turbo Codes

In this letter, we propose a hybrid turbo decoding algorithm, where the outer code, CRC code, is not used for error detection as usual but for error correction improvement. The algorithm combines the iterative decoding with ordered statistics decoding (OSD), where the CRC code and the turbo code are regarded as an integrated whole in the OSD process. Moreover, we propose an effective error detecting method based on normalized Euclidean distance to compensate for the loss of error detection capability which should have been provided by CRC. Simulation results show that with the proposed approach, 0.5-2dB performance gain can be achieved for the code blocks with short information length.