Arraycomm, Inc.

Intel Corporation

Swimc LLC

David M Parish

Craig H Barratt

Mitchell D Trott

Alain M Chiodini

Richard H Roy, Iii

Stephen J Sifferman

Christopher Richard Uhlik

Marc H Goldburg

Paul Petrus

Michael Youssefmir

Stephen P Boyd

Louis C Yun

Dov Rosenfeld

Farhad Farzaneh

Erik David Lindskog

Adam Bruce Kerr

John T Orchard

Serge Barbosa Da Torre

Bjorn E Ottersten

Athos Kasapi

Kamaraj Karuppiah

Chinping Q Yang

Stephen Boyd

Razi Anwer

Patrick D Ziemer

Richard H Roy

Richard H Iii Roy

Björn E Ottersten

Methods and apparatus implementing spatial processing in a remote unit. In general, in one aspect, the present invention provides a remote unit, that includes a plurality of antennas and a spatial processing unit coupled to the plurality of antennas. The remote unit also includes a performance determination unit to determine a performance of the remote unit and a feedback adjustment unit to adjust feedback transmitted from the remote unit to a device, wherein the adjusted feedback accounts for performance associated with the spatial processing unit.

Method and apparatus for adjusting feedback of a remote unit

This invention relates to a method and apparatus for transmitting a downlink signal from a communication station to one or more subscriber units to achieve a desired radiation level over a desired sector (e.g., everywhere), the communication station including an array of antenna elements and one or more signal processors programmed (in the case of programmable signal processors) to weight the downlink signal according to one of a sequence of complex valued weight vectors. The method includes sequentially repeating transmitting the downlink signal, each repetition with a different weight vector from the sequence until all weight vectors in the sequence have been transmitted with. The sequence is designed for achieving the desired radiation level during at least one of the repetitions. In this way, every user in the desired region is transmitted to in the time period.

Downlink broadcasting by sequential transmissions from a communication station having an antenna array

The present invention allows a radio receiver or a transmitter, with a plurality of antennas configured into an array, to be calibrated. In one embodiment, the method includes receiving a plurality of signals from a plurality of remote transmitters at the antenna array, sampling the signals received at at least two antennas of the array, computing a relative phase and amplitude of the sampled signals for each antenna, and computing calibration coefficients based on the relative phase and amplitude for the plurality of sampled signals from the plurality of remote transmitters for each antenna.

Statistical calibration of wireless base stations

Methods and apparatus implementing spatial processing in a remote unit. In general, in one aspect, a remote unit in accordance with the invention includes a plurality of antennas and a spatial processing unit coupled to the plurality of antennas.

Method and apparatus for providing spatial processing in a remote unit

A method for generating a reference signal from a modulated signal transmitted to a communications station that includes an array of antenna elements and spatial processing means including: separating from the signals received at the antenna elements a copy signal corresponding to the signal transmitted by a particular remote station using an initial spatial weight vector corresponding to the particular remote station; determining from the terminal copy signal a reference signal having substantially the same frequency offset and time alignment as the received antenna signals; and computing a new spatial weight vector by optimizing a cost function, the cost function using the received antenna signals and the reference signal. For demodulation, the method further includes extracting the symbols of the modulated signal.

Method for reference signal generation in the presence of frequency offsets in a communications station with spatial processing

Method for sequentially transmitting a downlink signal from a communication station that has an antenna array to achieve an omnidirectional radiation

A method operating in a communications station for calibrating the communications station, the communications station including an antenna array of antenna elements, each having associated with it and included in a transmit apparatus chain and a receiver apparatus chain. The method comprises transmitting a prescribed signal from each antenna element using the transmit apparatus chain associated with the antenna element while receiving the transmitted signal in receiver apparatus chains not associated with the antenna. Calibration factors for each antenna element are determined as dependent on the associated transmit apparatus chain and receiver apparatus chain transfer functions using the prescribed signal and each of the signals received during transmissions. A communications station also is described which includes: an antenna array of a plurality of elements, each antenna element having associated with it and included in a transmit apparatus chain and a receiver apparatus chain; transmitting means configured to transmit a prescribed signal from each antenna element while receiving the transmitted signal in at least one receiver apparatus chain not associated with the transmitting antenna element; a memory coupled to the receiver apparatus chains for storing the signals received during the transmissions of the prescribed signals; and a signal processor coupled to the memory and configured to determine calibration factors for each antenna element, the calibration factors for a particular antenna element based on the transmit apparatus chain and receiver apparatus chain transfer functions of the transmit and receiver apparatus chains, respectively, that are associated with the particular antenna element.

Method and apparatus for calibrating radio frequency base stations using

An RF-signal combiner-splitter comprises a microwave cavity that is intended to mix together radio signals in the 2.0 GHz spectrum. A hollow cylindrical metal tube with a volume of a few cubic feet to a few cubic yards is closed at one end and open at the other. Many RF-ports into the microwave cavity are provided at random positions that penetrate the hollow cylindrical metal tube. For example BNC-type bulkhead connectors with 10 dB attenuator pads are used with a 2 to 3 inch whip antenna inside the cavity volume. The attenuator pads brute-force an impedance match between the radio equipment under test and their corresponding RF-ports. The open end of the hollow cylindrical metal tube allows for the quick decay of RF-reflections that reverberate inside the cavity volume. Such open end is preferably directed toward nadir because interfering signals are generally minimum from that direction. In alternative embodiments, the cavity volume is partially filled with an RF-absorbing foam or other material to control reflections and limit the RF-energy within.

RF test fixture for adaptive-antenna radio systems

A method and apparatus for estimating the parameters of a wireless communication system which includes at least one base station and at least one remote terminal, each of the base stations having m antenna elements, the parameters being one or more of: the time alignment; the frequency offset; and the weight vector for spatial processing. At any stage, some of the parameters may already be estimated. A signal of known characteristics is transmitted and received as m received signals at the antenna elements. A cost function that is related to the at least one or more parameters of the second set is determined using a copy signal determined from samples of the received signals, estimates of one or more parameters, if available, known characteristics of transmitted first signal. The estimate of the parameters to be determined is obtained by minimizing the cost function.

Method and apparatus for estimating parameters of a communication system

A method and apparatus for generating a reference signal for use in an alternating projection loop which is part of demodulation in a base station of a wireless communication system, the reference signal relaxed to minimize the effects of frequency offset and amplitude variations, the base station including an array of antennas. The alternating projection loop demodulates in the presence of co-channel interference and includes correction for time alignment and/or frequency offset.

Method and apparatus for decision directed demodulation using antenna

A wireless system includes a network of base stations for receiving uplink signals transmitted from a plurality of remote terminals and for transmitting downlink signals to said plurality of remote terminals using a plurality of channels. A plurality of antenna elements at each base station receives uplink signals, and a plurality of antenna elements at each base station for transmits downlink signals. A signal processor at each base station is connected to the receiving antenna elements and to the transmitting antenna elements for determining spatio-temporal signatures. Spatio-temporal multiplexing and demultiplexing functions are provided for each remote terminal antennae for each channel, and a multiple base station network controller optimizies network performance, whereby communication between the base stations and the plurality of remote terminals in each of the channels can occur simultaneously.

Spectrally efficient high capacity wireless communication systems with

A wireless system comprising a network of base stations for receiving uplink signals transmitted from a plurality of remote terminals and for transmitting downlink signals to the plurality of remote terminals using a plurality of conventional channels including a plurality of antenna elements at each base station for receiving uplink signals, a plurality of antenna elements at each base station for transmitting downlink signals, a signal processor at each base station connected to the receiving antenna elements and to the transmitting antenna elements for determining spatial signatures and multiplexing and demultiplexing functions for each remote terminal antenna for each conventional channel, and a multiple base station network controller for optimizing network performance, whereby communication between the base stations and a plurality of remote terminals in each of the conventional channels can occur simultaneously.

Spectrally efficient high capacity wireless communication systems

A method and apparatus for calibrating antenna array systems comprising of a portable transponder (118) and a calibration processor (124). Calibration processor (124) generates calibration transmit signals which it transmits using transmit signal processor (104) and antenna array (111). Transponder (118) echoes these signals back and they are acquired by calibration processor (124) through antenna array (111) and receive signal processor (106). Calibration processor (124) processes the received signals to calculate antenna calibration vector (102).

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Amherst, NY, United States of America

David M Parish