Research Article
Butterfly-Flow-Graph Based MAP Decoding Algorithm for Channel Quality Information in 3GPP-LTE
@INPROCEEDINGS{10.1007/978-3-319-78139-6_21, author={Qi Li and He Wang and Yunchuan Yang and Bin Yu and Chengjun Sun}, title={Butterfly-Flow-Graph Based MAP Decoding Algorithm for Channel Quality Information in 3GPP-LTE}, proceedings={Communications and Networking. 12th International Conference, ChinaCom 2017, Xi’an, China, October 10-12, 2017, Proceedings, Part II}, proceedings_a={CHINACOM}, year={2018}, month={4}, keywords={3GPP-LTE CQI MAP decoding}, doi={10.1007/978-3-319-78139-6_21} }- Qi Li
He Wang
Yunchuan Yang
Bin Yu
Chengjun Sun
Year: 2018
Butterfly-Flow-Graph Based MAP Decoding Algorithm for Channel Quality Information in 3GPP-LTE
CHINACOM
Springer
DOI: 10.1007/978-3-319-78139-6_21
Abstract
Channel quality information (CQI) is an essential element of uplink control signaling in Long Term Evolution (LTE) system. According to 3GPP standard, a linear block code based on Reed-Muller (RM) code has been employed for the CQI transmission for error control. In this paper, a low complexity (MAP) decoding algorithm for CQI decoding is described, which is performed by re-ordering the likelihood values of the received signal and all mapped codewords, and then calculating the probability of 0 and 1 of every transmitted information bit based on a butterfly-flow-graph (BFG). Compared to the standard MAP decoding algorithm, the proposed algorithm can reduce the addition calculation by 35.71% to 72.82% when the number of CQI bit is changing from 4 to 11, and the bit error rate (BER) performance is without degradation.