Phase jitter compensation arrangement using an adaptive IIR filter
US4847864A · kind A · utility
Assignees
Inventor
Key dates
| Filing date | Jun 22, 1988 |
| Grant date | Jul 11, 1989 |
| Priority date | — |
| Expiry date | Jun 22, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/01
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A voice-band data symbol is typically impaired by so-called phase jitter prior to symbol being received at a data modem. Modem circuitry estimates the phase angle of the jitter and an infinite-impulse-response (IIR) filter adjusts to that phase angle so that the jitter can be corrected for by a demodulator circuit. Advantageously, the IIR filter is arranged so that its pair of complex, conjugate poles are initially positioned at a first predetermined radius within a unit circle. The angular displacement of the poles around the unit circle is adaptively increased in response to receipt of a series of such estimates until such displacement substantially equals the phase angle of the jitter. The poles are then positioned at a second predetermined radius to increase the gain of the filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.