Hybrid annihilation transformation (HAT) for pipelining QRD-based least-square adaptive filters

Zhipei Chi, Jun Ma, Keshab K. Parhi

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


A novel transformation referred to as hybrid annihilation transformation (HAT) for pipelining the QR decomposition (QRD) based least square adaptive filters has been developed. HAT provides a unified framework for the derivation of highthroughput/low-power VLSI architectures of three kinds of QRD adaptive filters namely QRD recursive least-square (LS) adaptive filters QRD LS lattice adaptive filters and QRD multichannel LS lattice adaptive filters. In this paper HAT is presented as a solution to break the bottleneck of a high-throughput implementation introduced by the inherent recursive computation in the QRD based adaptive filters. The most important feature of the proposed solution is that it does not introduce any approximation in the entire filtering process. Therefore it causes no performance degradation no matter how deep the filter is pipelined. It allows a linear speedup in the throughput rate by a linear increase in hardware complexity. The sampling rate can be tradedoff for power reduction with lower supply voltage for applications where high-speed is not required. The proposed transformation is addressed both analytically with mathematical proofs and experimentally with computer simulation results on its applications in wireless code division multiple access (CDMA) communications conventional digital communications and multichannel linear predictions.

Original languageEnglish (US)
Pages (from-to)661-674
Number of pages14
JournalIEEE Transactions on Circuits and Systems II: Analog and Digital Signal Processing
Issue number7
StatePublished - Jul 2001

Bibliographical note

Funding Information:
Manuscript received July 27, 1999; revised June 19, 2001. This work was supported by the U.S. Department of Defense Advanced Research Projects Agency under Contract DA/DABT 63-96-C-0050. This paper was recommended by Associate Editor K. Jenkins.


  • Adaptive filtering
  • Algorithm transformations
  • High speed (high throughput)
  • LSL
  • Multichannel lsl
  • Parallel processing
  • Pipelining
  • RLS


Dive into the research topics of 'Hybrid annihilation transformation (HAT) for pipelining QRD-based least-square adaptive filters'. Together they form a unique fingerprint.

Cite this