Amplifiers – With amplifier condition indicating or testing means
Reexamination Certificate
1999-02-05
2001-04-10
Mottola, Steven J. (Department: 2817)
Amplifiers
With amplifier condition indicating or testing means
C330S304000, C330S126000
Reexamination Certificate
active
06215354
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to the field of signal amplification; more particularly, the present invention relates to amplifying multiple radio frequency (RF) carrier signals with saturated or nearly saturated amplifiers with low distortion meeting the requirements of many cellular or wireless communication systems such as, for example, those meeting AMPS, TDMA, GSM and CDMA requirements.
BACKGROUND OF THE INVENTION
Cellular telephone systems are an important example of a mobile communication system. Cellular mobile telephone systems may be categorized according to those using analog modulation and those using digital modulation. One of the most widely used cellular telephone system is commonly known as the Advanced Mobile Phone System (AMPS).
An AMPS cellular telephone system typically includes a mobile telecommunication switching office (MTSO), a number of base stations (cell sites), a data link network, optional repeaters and converters, and mobile subscriber units (e.g., mobile phones). The MTSO is a special purpose switch that connects calls between mobile units and a landline telephone network. The MTSO functions to assign a voice channel to each base station. The data link network carries data between the base stations and the MTSO, and may include wired or wireless communication links. Each base station typically comprises an antenna, a controller and a number of transceivers. The controller handles the process of connecting a call between the switching system and the mobile units via a set-up channel. A mobile unit comprises a transceiver and a control unit to perform two-way communication.
These telephone systems often employ modems to transfer information between the MTSO and the transceivers. Equalization is commonly performed on a single channel. For instance, single channel equalization is often used in modems to reduce distortion on the incoming signal due to the effects of the channel. In other words, the equalizer in the modem compensates for the effects of the wire line to the signal receive location.
Other cellular telecommunication systems in use include a time-division multiple-access (TDMA) system and a code-division multiple access (CDMA) system, which are named for the type of digital modulation they employ. The European digital cellular system is known as the Global System for Mobile Communications (GSM). This system uses TDMA modulation. However, CDMA is fast becoming the standard and replacing many TDMA systems. The IS95 North American digital cellular system uses CDMA modulation.
SUMMARY OF THE INVENTION
A calibration method and apparatus for calibrating a linear amplifier is described. One embodiment of the method includes modeling the amplifier channel and the amplifier to generate an estimated amplifier transfer function for each channel in the channel pair. Using the estimated data channel amplifier transfer function for each channel, equalizer values (e.g., coefficient values) are computed for equalizers that are applied to each channel in the channel pair prior to amplification.
REFERENCES:
patent: 5500626 (1996-03-01), Barclay
patent: 5886573 (1999-03-01), Kolanek
patent: 5955917 (1999-09-01), Mandell et al.
Baseghi Behshad
Kolanek James C.
Shynk John J.
Blakely , Sokoloff, Taylor & Zafman LLP
Fujant, Inc.
Mottola Steven J.
LandOfFree
Closed loop calibration for an amplitude reconstruction... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Closed loop calibration for an amplitude reconstruction..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Closed loop calibration for an amplitude reconstruction... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2535569