Dual-mode cellular telephone system

Details Dual-mode cellular telephone system Dual-mode cellular telephone system

1997-06-04

2000-03-07

Eisenzopf, Reinhard J.

Telecommunications

Transmitter and receiver at same station

Radiotelephone equipment detail

370441, 455296, H04B 138

Patent

active

060352132

ABSTRACT:
A dual-mode cellular telephone system which is capable of suppressing a narrow-band disturbing signal appearing in a mobile station of a dual-mode cellular telephone system adapted for both an analog system and a digital CDMA system. A CDMA signal from a CDMA base station, and a narrow-band signal from an analog system are received through an antenna by a receiver, whereby they are amplified, subjected to frequency conversion, and input to a variable notch filter. A disturbing signal detection circuit supplies the variable notch filter with a control signal for varying its frequency. Namely, the disturbing signal detection circuit detects a case that an output level of the variable notch filter is at a minimum by changing the notch frequency via a series of sweeping control signals. A control signal at which the output level of the variable notch filter is at a minimum is then fed to the variable notch filter, thereby effectively suppressing any intermodulation distortions present in the mobile station.

REFERENCES:
patent: 5222144 (1993-06-01), Whikehart
patent: 5226057 (1993-07-01), Boren
patent: 5325188 (1994-06-01), Scarpa
patent: 5469115 (1995-11-01), Peterzell et al.
patent: 5584056 (1996-12-01), Kim
patent: 5596600 (1997-01-01), Dimos et al.
patent: 5640385 (1997-06-01), Long et al.
patent: 5758296 (1998-05-01), Nakamura

Affiliated with

Also associated with

Rating

Dual-mode cellular telephone system does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Dual-mode cellular telephone system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dual-mode cellular telephone system will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-371838