Paper Info
Title
Optimal Datapath Widths Within Turbo and Viterbi Decoders for High Area- and Energy-Efficiency.
Abstract
Datapath widths in state-of-the-art Turbo and Viterbi decoder implementations depend on estimated upper bounds of the differences of processed metrics. Aiming at highest area and energy efficiency, this paper presents guidelines for designing Turbo and Viterbi decoder datapaths with minimal widths. This is based on maximum absolute values of branch, state and path metric differences within theMax-Log-MAP respectively Viterbi decoding algorithm applying modulo normalization. The proposed methodology for determining the maximum absolute values covers punctured as well as n-input binary convolutional and Turbo codes so it accommodates higherradix add-compare-select operations. Maximum absolute values of metric differences and minimum datapath widths are presented for the 3GPP-LTE, DVB-RCS2 and IEEE-802.16 (WiMAX) compliant Turbo decoders and for the IEEE-802.11 (Wi-Fi), IEEE-802.16 (WiMAX) and 3GPP-LTE compliant Viterbi decoders. Besides, a new dynamic branch-metric saturation scheme is presented, which enables a further datapath width reduction within Turbo decoders. In total, a datapath width reduction of two bits (¿20 %) is achieved applying radix-4 Max-Log-MAP arithmetic. An overall area-time-energy complexity reduction of 31% is achieved for a soft-input soft-output decoder and of 24% for the LTE Turbo decoder.
Year
DOI
Venue
2017
10.1007/s11265-016-1140-7
Signal Processing Systems
Keywords
Field
DocType
Turbo decoder,Iterative decoding,Soft-input soft-output decoder,Maximum-a-posteriori algorithm,Modulo normalization,Dynamic branch-metric saturation
Turbo,Datapath,Soft output Viterbi algorithm,Computer science,Turbo code,Real-time computing,Viterbi decoder,Soft-decision decoder,Turbo equalizer,Viterbi algorithm
Journal
Volume
Issue
ISSN
87
3
1939-8018
Citations 
PageRank 
References 
0
0.34
25
Authors
2
Name
Order
Citations
PageRank
Martin Broich100.34
Tobias G. Noll219937.51