Tail-Overlapped SISO Decoding for High-Throughput LTE-Advanced Turbo Decoders

摘要

This paper proposes a novel decoding algorithm to enhance the throughput of turbo decoding in LTE-Advanced systems and its hardware realization. The proposed method completely removes the undesired phase-switching latency by partially overlapping in-ordered and interleaved decoding phases, and as a result, achieves a significant increase of decoding throughput. Moreover, the algorithm does not degrade error-correcting performance for high-rate codes which are essential to achieve the maximum data rate of LTE-Advanced systems. The proposed method called tail-overlapped decoding can be easily applied to the conventional parallel decoding architecture designed for standardized communication systems. In addition, a new structure for the extrinsic information memory is proposed to eliminate memory contentions. A 3GPP LTE-Advanced turbo decoder supporting both decoding methods is implemented in 0.13 $mu$m CMOS technology to show the effectiveness of the proposed algorithm. The decoder exhibits a decoding rate greater than 1Gbps with six iterations, meeting the peak data rate of the LTE-Advanced standard with much less hardware complexity than those of the previous works.