At&t Wireless Services, Inc.

At&t Mobility Ii LLC

Freewave Technologies, Inc.

Cingular Wireless Ii, LLC

Gregory J Veintimilla

Michael Hirano

Elliott Hoole

Hongliang Zhang

Siavash Alamouti

Mary Jesse

Eduardo F Casas

Patrick Poon

David G Michelson

Steven E McMeekin

Timothy G Mester

Robert Lee Maxwell

David J Nix

David B Gibbons

David J Ryan

James Timothy Golden

Adrian Yip

Jeffrey Battin

Padma P Mallela

A method for operating a downlink transmitter radio to automatically determine transmission parameters includes monitoring the spectral content of a range of frequencies, and identifying, based on the monitored spectral content, spectral characteristics associated with noise or interference. The downlink transmission channel carrier frequency and channel frequency bandwidth are determined based on the spectral characteristics of the interference together with operating requirements of the wireless transmission system.

Dynamic and flexible channel selection in a wireless communication system

A broadband transceiver includes an input to receive an RF signal, an output to output an RF transmit signal, a receiver section coupled to the input, and a transmitter section coupled to the output. A processor coupled to the receiver section and the transmitter section determines and generates an inverse waveform that will result in attenuation of undesired portions of a received RF signal when summed with the received signal, including optionally at one or more of an RF stage and an IF stage. A summing junction coupled between the processor and receiver section sums the inverse waveform with the received signal.

Pre-distortion of receive signal for interference mitigation in broadband transceivers

A broadband superheterodyne receiver. Embodiments include an input for receiving an RF signal including an RF data signal at a carrier frequency. An RF mixer coupled to the input shifts the RF data signal from the carrier frequency to an IF frequency. An IF band pass filter coupled to the mixer has a pass band, and band pass filters the signal near the IF frequency. A spectrum analyzer provides information representative of the spectral characteristics of the received RF signal around the RF data signal at the carrier frequency. An IF controller is coupled to the RF mixer and to the spectrum analyzer. The IF controller: (1) determines an interference-mitigating IF frequency within the pass band of the band pass filter that will result in attenuation of undesired portions of the RF signal, and (2) controls the RF mixer to shift the RF data signal to the interference-mitigating IF frequency.

Broadband superhetrodyne receiver with agile intermediate frequency for interference mitigation

The high quality PCS communications are enabled in environments where adjacent PCS service bands operate with out-of-band harmonics that would otherwise interfere with the system's operation. The highly bandwidth-efficient communications method combines a form of time division duplex (TDD), frequency division duplex (FDD), time division multiple access (TDMA), orthogonal frequency division multiplexing (OFDM), spatial diversity, and polarization diversity in various unique combinations. The method provides excellent fade resistance. The method enables changing a user's available bandwidth on demand by assigning additional TDMA slots during the user's session.

Method for frequency division duplex communications

A fixed wireless system (FWS) utilizing Orthogonal Frequency Division Multiplexing (OFDM) communication techniques is spectrally efficient and responsive to communications involving both voice and high speed data, such as Internet data. The FWS includes a wireless base unit; a plurality of fixed wireless remote units; a plurality of wireless data traffic channels available between the wireless base unit and the plurality of fixed wireless remote units; and a plurality of wireless voice traffic channels available between the wireless base unit and the plurality of fixed wireless remote units. Each wireless traffic channel is identifiable by a unique combination of frequency and time slots. Each wireless data traffic channel is used for carrying high speed data in addressed data packets to and from the plurality of fixed wireless remote units. On the other hand, each wireless voice traffic channel can be assigned and dedicated to a particular voice communication call involving one of the plurality of fixed wireless remote units for carrying voice data of the call.

Methods and apparatus for use in communicating voice and high speed data in a wireless communication system

An apparatus and method provide for synchronized operation of encryption processes at two remote communication terminals. A first one of the terminals detects information associated with a current time during the establishment of a connection between the two terminals. The current time information is then utilized to create a start encryption time. That start encryption time information is transmitted from the first terminal to the second terminal. Both terminals then monitor the passage of time and begin encryption in a synchronous manner when the current time matches the start encryption time.

Method for synchronous encryption over a communication medium

A method for a wireless discrete multitone spread spectrum communications system, synchronizes the remote station to the base station. The method begins with the step of generating a clock signal at the base station. The base station then derives a synchronization symbol pattern from the base station clock signal and spreads the it with spreading codes that distributes the symbol pattern over a plurality of discrete tones, forming a discrete multitone spread spectrum signal. The base station then transmits the spread signal to the remote station. The remote station generates a first clock signal and samples the discrete tones using the remote station first clock signal, forming a first sampled signal. Then the remote station applies the first sampled signal to a matched filter bank, forming a frequency error signal. The method then adjusts a frequency of the remote station first clock signal using the frequency error signal, forming a second clock signal. Then the remote station samples the discrete tones using the remote station second clock signal, forming a second sampled signal. Then the remote station despreads the second sampled signal with despreading codes to extract the synchronization symbol pattern. Then the remote station compares the extracted synchronization symbol pattern with a reference symbol pattern at the remote station. If the comparing step is successful, then the remote station selectively processes traffic signals received from the base station using the second clock signal. If the comparing step is not successful, then the remote station selectively adjusts a time offset value of the remote station second clock signal forming a third clock signal. The remote station then samples the discrete tones using the remote station third clock signal, forming a third sampled signal. The remote station then despreads the third sampled signal with despreading codes to form a second extraction of the synchronization symbol pattern. The remote station then compares the second extraction of the synchronization symbol pattern with the reference symbol pattern at the remote station. If the step of comparing the second extraction is successful, then the remote station selectively processes traffic signals received from the base station using the third clock signal.

Method to indicate synchronization lock of a remote station with a base

A method for a wireless discrete tone communications system, synchronizes the remote station to the base station. The method begins with the step of generating a clock signal at the base station. The base station then derives a synchronization symbol pattern from the base station clock signal and spreads the it with spreading codes that distributes the symbol pattern over a plurality of discrete tones, forming a discrete tone signal. The base station then transmits the spread signal to the remote station. The remote station generates a first clock signal and samples the discrete tones using the remote station first clock signal, forming a first sampled signal. Then the remote station applies the first sampled signal to a matched filter bank, forming a frequency error signal. The method then adjusts a frequency of the remote station first clock signal using the frequency error signal, forming a second clock signal. Then the remote station samples the discrete tones using the remote station second clock signal, forming a second sampled signal. Then the remote station despreads the second sampled signal with despreading codes to extract the synchronization symbol pattern. Then the remote station compares the extracted synchronization symbol pattern with a reference symbol pattern at the remote station. If the comparing step is successful, then the remote station selectively processes traffic signals received from the base station using the second clock signal. If the comparing step is not successful, then the remote station selectively adjusts a time offset value of the remote station second clock signal forming a third clock signal. The remote station then samples the discrete tones using the remote station third clock signal, forming a third sampled signal. The remote station then despreads the third sampled signal with despreading codes to form a second extraction of the synchronization symbol pattern. The remote station then compares the second extraction of the synchronization symbol pattern with the reference symbol pattern at the remote station. If the step of comparing the second extraction is successful, then the remote station selectively processes traffic signals received from the base station using the third clock signal.

Growing community of inventors

Redmond, WA, United States of America

Gregory J Veintimilla