An Improved Pipelined MSB-First Add-Compare Select Unit Structure for Viterbi Decoders
Author:
- 22 March 2004
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Circuits and Systems I: Regular Papers
- Vol. 51 (3) , 504-511
Abstract
Convolutional codes are widely used in many communication systems due to their excellent error-control performance. High-speed Viterbi decoders for convolutional codes are of great interest for high-data-rate applications. In this paper, an improved most-significant-bit (MSB) -first bit-level pipelined add-compare select (ACS) unit structure is proposed. The ACS unit is the main bottleneck on the decoding speed of a Viterbi decoder. By balancing the settling time of different paths in the ACS unit, the length of the critical path is reduced as close as possible to the iteration bound in the ACS unit. With the proposed retimed structure, it is possible to decrease the critical path of the ACS unit by 12% to 15% compared with the conventional MSB-first structures. This reduction in critical path can reduce the level of parallelism (and area) required for a very high-speed Viterbi decoder.Keywords
This publication has 8 references indexed in Scilit:
- A 210 Mb/s radix-4 bit-level pipelined Viterbi decoder2002
- Implementation of scalable power and area efficient high-throughput Viterbi decodersIEEE Journal of Solid-State Circuits, 2002
- A 550 Mb/s radix-4 bit-level pipelined 16-state 0.25-μm CMOS Viterbi decoder2000
- A 1-Gb/s, four-state, sliding block Viterbi decoderIEEE Journal of Solid-State Circuits, 1997
- A 140-Mb/s, 32-state, radix-4 Viterbi decoderIEEE Journal of Solid-State Circuits, 1992
- High-rate Viterbi processor: a systolic array solutionIEEE Journal on Selected Areas in Communications, 1990
- Parallel Viterbi algorithm implementation: breaking the ACS-bottleneckIEEE Transactions on Communications, 1989
- Error bounds for convolutional codes and an asymptotically optimum decoding algorithmIEEE Transactions on Information Theory, 1967