Channel equalisers
US6636561B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 29, 1999 |
| Grant date | Oct 21, 2003 |
| Priority date | — |
| Expiry date | Jun 29, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2025/03605
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The present invention provides a method whereby an adaptive equaliser is applied to the terminal (mobile) receivers in a cellular radio CDMA system whose purpose is to minimise the mutual interference between users sharing the same radio channel. The application relevant to third generation cellular systems which consist of UTRA (or WBCDMA) in Europe and CDMA2000 in the USA (or future merged standards variants of these systems), and has a special application to the time domain duplex (TDD) mode of these systems. An algorithm is provided whereby the equaliser is adapted to conform to some recognised optimality criterion which is known to lead to a minimum mutual interference situation. One method is the constrained minimum output finite impulse response (FIR) digital filter power condition, but the technique is not limited to this criterion. The method reduces the computation load of a digital filter by selecting a sparse subset of delay line taps which are actively weighted and used as a filter. The rest of the delay line taps are ignored. The active subsets are optimized.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.