A Comparison of the Performance of 'Pruned Tree' versus 'Stack" Algorithms for Look-Ahead Sigma delta Modulators

Angus, JAS

Abstract

Look-ahead Sigma-Delta modulators look forward k samples before deciding to output a “one” or a “zero”. The Viterbi algorithm is then used to search the trellis of the exponential number of possibilities that such a procedure generates. This paper describes alternative tree based algorithms. Tree based algorithms are simpler to implement because they do not require backtracking to determine the correct output value. They can also be made more efficient using “Stack” algorithms. Both the tree algorithm and the more computationally efficient “Stack” algorithms are described. Implementations of both algorithms are described in some detail. In particular, the appropriate data structures for both the trial filters and score memories. Comparative results of their performance are also presented.

Citation

Angus, J. (2006). A Comparison of the Performance of 'Pruned Tree' versus 'Stack" Algorithms for Look-Ahead Sigma delta Modulators. Journal of the Audio Engineering Society, 54(6), 477-494

• Journal Article Type: Article
• Publication Date: Jun 1, 2006
• Deposit Date: Sep 10, 2007
• Journal: Journal of the Audio Engineering Society
• Print ISSN: 1549-4950
• Publisher: Audio Engineering Society
• Peer Reviewed: Peer Reviewed
• Volume: 54
• Issue: 6
• Pages: 477-494
• Publisher URL: http://www.aes.org/tmpFiles/elib/20070509/13687.pdf