Method and a device for maintaining the performance quality of a code-division multiple access system in the presence of narrow band interference
US6807405B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 28, 1999 |
| Grant date | Oct 19, 2004 |
| Priority date | — |
| Expiry date | Apr 28, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B2201/709718
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method and device which dynamically detects, tracks and filters interfering signals with sufficient speed (i.e. within one IS-95 CDMA data. frame period, or 20 ms) and fidelity to eliminate or greatly reduce the deleterious effects of narrow band interferer signals on a CDMA link. When inserted in an RF signal path an Adaptive Notch Filter (ANF) detects narrow band interferors above a threshold level within the CDMA signal. Detection is accomplished by continuous scanning of a preset excision band, e.g. a specified narrow band associated with an AMPS system. Detected interferors are then automatically acquired and suppressed. This is achieved by electronically placing a rejection notch at the frequency of the interferors. Multiple notch filters may be used to simultaneously suppress multiple interferors. In the absence of interferors a bypass mode is selected allowing the RF signal to bypass the notch. Upon detection of an interferer, a switch is made to a suppression mode where the interferor is steered through a first notch section and suppressed. Alternatively, an external control line may be used to select the bypass mode so that the signal is allowed to pass the notch sectio…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.