Methods and apparatus for adaptive signal processing involving a Karhunen-Loève basis
US6993477B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 8, 2000 |
| Grant date | Jan 31, 2006 |
| Priority date | — |
| Expiry date | Oct 10, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L25/48
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A signal processing device utilizes a stochastic approximation of a gradient descent algorithm for updating a transform. The signal processing device is configured to implement the transform for producing a desired transformed output signal, and the transform is updated using the stochastic approximation of the gradient algorithm based on received data associated with the signal being processed. The transform is represented in a reduced-parameter form, such as a Givens parameterized form or a Householder form, such that the reduced-parameter form for an N×N transform comprises fewer than N2 parameters. The updating process is implemented using computations involving the reduced-parameter form, and an adaptation of the transform is represented directly as one or more changes in the reduced-parameter form. The gradient algorithm may be configured to minimize a negative gradient of a pairwise energy compaction property of the transform. Advantageously, the gradient algorithm may be made locally convergent in mean for a specified step size. The invention can also be implemented in a backward adaptive form in which the updating process is driven by quantized data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.