Arraycomm, Inc.

Intel Corporation

Louis C Yun

Mitchell D Trott

Christopher Richard Uhlik

Craig H Barratt

Marc H Goldburg

Tibor Boros

David M Parish

Stephen P Boyd

Mark C Leifer

Paul Petrus

Bjorn E Ottersten

David Depierre

Antoine Chemali

Stephen Boyd

A method for power control with signal quality estimation for smart antenna communications system is described. The method, for example, starts with a transmit power assignment. Receive weight vector determination is carried out with this assigned transmit power, and the new weights used. An estimate of the resulting received signal quality is obtained and used for another power adjustment.

Power control with signal quality estimation for smart antenna communications systems

A method and apparatus is described for modifying a smart antenna processing strategy determined from a set of signals received at an array of antenna elements of a wireless station, such as a set of weights for processing received antenna signals or forming a set of antenna signals for transmission. The method and apparatus uses the signatures of one or more interferers to produce a modified processing strategy that improves the nulling to the one or more interferers in that, when the modified strategy is applied on the downlink, the transmit signal strength in the direction of the one or more interferers is decreased, and, when the modified strategy is applied on the uplink, the sensitivity to signals from the direction of the one or more interferers is decreased.

Null deepening for an adaptive antenna based communication station

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

A method for ongoing power control for a communication station with a multiple antenna array, the power control using a method for signal quality estimation applicable for angle modulated signals. One aspect of the ongoing power control method is applicable for the uplink and includes separating the joint determination of a receive weight vector and ongoing power control into a receive weight vector determining part and a separate transmit power adjustment part. In one embodiment, the ongoing power control method for the downlink includes separating the joint determination of a receive weight vector and ongoing power control into a receive weight vector determining part and a separate transmit power adjustment part. The method starts with one part, for example transmit power assignment. Receive weight vector determination is carried out with this assigned transmit power, and the new weights used. An estimate of the resulting received signal quality is obtained and used for new ongoing power adjustment. Another aspect is applicable for the downlink and includes one aspect of the ongoing power control method is applicable for the uplink and includes separating the determination of a complete transmit weight vector including the vector of relative transmit weights and the scaling to use with the relative transmit weights into a part for determining a set of relative transmit weights and a separate transmit power adjustment part that determines the scaling factor.

Power control with signal quality estimation for smart antenna communication systems

The present invention is a method for operating a base station (BS) for transmitting information to a subscriber unit (SU) in a cellular communication system. The information is included in a downlink signal sent from a signal processing circuit through an array of antennae. The processing depends on a weight set that is utilized in generating individual signals to be sent on individual antennae in the array to the SU. The weight set is determined by transmitting a plurality of pilot downlink signals from BS to the SU, each pilot downlink signal being processed with a different weight set than that used to process the other pilot downlink signals. Report signals are received for each of the pilot downlink signals and are compared to determine which weight set should be utilized. The present invention may be practiced within existing CDMA cellular standards such as the IS-95 standard.

Downlink signal processing in CDMA systems utilizing arrays of antennae

A downlink beamforming apparatus and method. In one embodiment, a method in accordance with the teachings of the present invention includes receiving uplink communication signals from a plurality of antenna array elements, selecting an operating condition of an environment and estimating downlink beamforming weights used in downlink communication signals in response to the selected operation condition of the environment.

Method and apparatus for estimating downlink beamforming weights in a communications system

A method for ongoing power control for a communication station with a multiple antenna array, the power control using a method for signal quality estimation applicable for angle modulated signals. One aspect of the ongoing power control method is applicable for the uplink and includes separating the joint determination of a receive weight vector and ongoing power control into a receive weight vector determining part and a separate transmit power adjustment part. In one embodiments, The ongoing power control method for the downlink includes separating the joint determination of a receive weight vector and ongoing power control into a receive weight vector determining part and a separate transmit power adjustment part. The method starts with one part, for example transmit power assignment. Receive weight vector determination is carried out with this assigned transmit power and the new weights used. An estimate of the resulting received signal quality is obtained and used for new ongoing power adjustment. Another aspect is applicable for the downlink and includes one aspect of the ongoing power control method is applicable for the uplink and includes separating the determination of a complete transmit weight vector including the vector of relative transmit weights and the scaling to use with the relative transmit weights into a part for determining a set of relative transmit weights and a separate transmit power adjustment part that determines the scaling factor.

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

An adaptive method for channel assignment in a cellular multiple access wireless communication system that has a cell station (CS) and a number of subscriber stations augments existing channel assignment protocol and thus is downward compatible with existing time division multiple access (TDMA), frequency division multiple access (FDMA), code division multiple access (CDMA), and spatial division multiple access (SDMA) system protocols. The method adaptively determines the power required for establishing an acceptable quality connection between a subscriber station and the cell station and provides an early warning trial signal for advising existing connections that a new connection is about to be established. The early warning, followed by a pause, provides a basis and a time interval for taking corrective interference action if the trial signal indicates that an unacceptable level of interference will result if the trial connection is established. The early warning signal and associated pause are useful for intracellular and intercellular interference management.

Adaptive method for channel assignment in a cellular communication system

A wireless communication subscriber unit comprises a radio frequency downconversion stage that produces in-phase and quadrature phase digital samples. A digital signal processor is connected to receive the samples and process them to produce a control channel correlation output and a carrier frequency offset estimate. The acquisition of the control channel is made substantially immune from initial carrier frequency offsets by differential sample encoding the samples. These are input to a correlator whose coefficients are a pre-stored differential sample encoded, decimated and rate expanded version of the known reference sequence. When the the reference sequence is present, the correlator produces a peak output that can be used to detect the presence of the reference sequence. The time position of the peak can be used for time alignment, for signal quality estimation, and to directly obtain a frequency offset estimate.

Method and system for rapid initial control signal detection in a

The methods for channel assignment and channel reassignment are suitable for SDMA systems that accommodate the dynamically adaptive spatial channel conditions and allow for more frequent reuse of conventional channels. Three methods for uplink channel assignment are described: a cost function method, a predictive method, and a hierarchical method. The cost function method computes a cost function for each conventional channel based on a weighted correlation matrix of spatial signatures (vectors) of active subscribers. A spatial channel is created for the selected conventional channel if it is in use. The predictive channel assignment method predicts the uplink received power and interference-plus-noise for each conventional channel. Either the conventional channel with the minimum interference-plus-noise level or the channel with the maximal SINR is selected and a spatial channel is also assigned if the selected channel is in use. The hierarchical method combines the cost function method and the cost function method. The downlink channel assignment method, when not constrained by the uplink channel assignment, assigns a conventional channel to a new connection by estimating the downlink interference-plus-noise level from a subscriber report, spatial signature and weight vector, and computing a predicted downlink received signal level. Three methods for call admission control include: a cost function method, a predictive method, and a load based channel assignment method.

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Santa Clara, CA, United States of America

Louis C Yun