Abstract: A method and apparatus for mitigating co-channel and inter-channel interference in an antenna array system. According to one aspect, the channel-select filter of a base station or other communication device is modified to detect inter-channel interference on at least one non-primary channel when the transmitter is communicating with a remote user terminal on a primary channel. The spatial characteristic of the interference is determined and used to obtain a weight that mitigates the inter-channel interference. According to another aspect, the spatial characteristic of co-channel and/or inter-channel ghost signal interference caused by a transmitter is determined and used to mitigate the effects of such interference.

Abstract: 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.

Abstract: In one embodiment, the present invention comprises demultiplexing a bit stream into a first block and a second block, convolutionally coding the first block and block coding the second block. The invention further comprises applying the block coded second block to a function module to apply one of a plurality of different functions to form a third block at an output of the module and mapping the convolutionally coded first block and the third block to a modulation constellation for transmission, the mapping resulting in different constellation points depending on the applied function.

Abstract: A method and apparatus are provided that provide bandwidth efficient variable bit rate communication of digital signals in a noisy channel. According to one aspect of the present invention, the invention includes receiving a puncturing request, puncturing a data packet in accordance with the puncturing request, creating a puncturing code indicating the puncturing that has been applied to the data packet and transmitting the punctured data packet and the puncturing code.

Abstract: A partial spatial signature can be determined to be used in calibration. In one embodiment, determining the partial spatial signature includes receiving a first segment of a waveform, the first segment resulting from a radio transmitting a combined signal from a first antenna element, the combined signal comprising the sum of a first signal and a second signal, and calculating a first spatial signature related measurement using the received first segment, the first signal and the second signal. The process may further include receiving a second segment of the waveform, the second segment resulting from the radio transmitting the first signal from the first antenna element, and the radio simultaneously transmitting the second signal from a second antenna element, and calculating a second spatial signature related measurement using the second received segment, the first signal, and the second signal.

Abstract: A calibration function for calibrating a base station can be determined using one or more remote terminals. In one embodiment of the present invention, determining the calibration function includes transmitting a calibration signal, using an array of antenna elements of a first radio, to a second radio, and receiving, at the first radio, a downlink spatial signature related signal from the second radio containing information related to a second radio downlink spatial signature, the information being calculated using the calibration signal. Then, a second radio downlink spatial signature may be determined using the downlink spatial signature related signal. Also, a second radio uplink spatial signature may be determined using an uplink spatial signature signal from the second radio to the first radio. The calibration function may then be determined using the second radio downlink spatial signature and the second radio uplink spatial signature.

Abstract: A method and apparatus are provided that performs spatial processing, timing estimation and frequency offset using a training sequence of a received burst. According to one aspect of the present invention, the invention includes receiving a burst having a known training sequence at a set of diversity antennas, sampling the received burst at each antenna, determining a coarse timing estimate for samples from at least one antenna, and determining a spatial weighting vector using the coarse timing estimate. The embodiment further includes applying the spatial weighting vector to the received burst samples for each antenna to form a single channel signal, determining a fine timing estimate for the single channel signal, determining a second spatial weighting vector using the fine timing estimate, applying the second spatial weighting vector to the received burst samples for each antenna to form a second single channel signal, and demodulating the second single channel signal.

Abstract: A method and apparatus are provided that allows initial beamforming weights to be determined before timing or delay and frequency offset are known. According to one aspect of the present invention, the invention includes receiving a burst from a terminal at a set of spatial diversity antennas, the burst including a known training sequence and storing measurements of the received burst from each spatial diversity antenna corresponding to receive times within a selected analysis window. The invention further includes determining weights for each diversity antenna for at least a portion of the training sequence of the burst before timing for the burst has been determined, applying the determined weights to the stored measurements and determining timing for the burst based on the stored measurements to which the determined weights have been applied.

Abstract: In one embodiment, the present invention comprises a demultiplexer to divide a bit stream into a first block at a first output and a second block at a second output, a convolutional coder coupled to the first output to encode the first block and a block coder coupled to the second output to encode the second block. The invention further includes a function module coupled to the block coder to apply one of a plurality of different functions to the encoded second block to produce a third block at an output and a mapper coupled to the function module output and to the convolutional coder to map the third block from the output of the function module and the encoded first block into one of a plurality of modulation constellations. A controller is coupled to the demultiplexer to control the size of the first and second blocks, is coupled to the block coder to control the block coding, and is coupled to the function module to control the function to be applied.

Abstract: A method and apparatus for estimating the downlink signature for a remote transceiver which is part of a wireless communication system that includes a main transceiver for communicating with the remote transceiver. The main transceiver includes an array of transmit antenna elements. The method uses the remote transceiver for receiving signals when the main transceiver transmits downlink calibration signals. When the main transceiver also has a receive antenna array, the remote transceiver can transmit uplink calibration signals to the main transceiver for determining an uplink signature. The downlink and uplink signatures are used to determine a calibration function to account for differences in the apparatus chains that include the antenna elements of the arrays, and that enable downlink smart antenna processing weights to be determined from uplink smart antenna processing weights when the main transceiver includes means for smart antenna processing according to weights.

Abstract: An emergency call recognition system which is activated when an off-hook situation occurs, which recognizes when an emergency number is dialed with or without the presence of a dial tone, and which provides the caller a communication channel to complete such a call. The present invention is used to give priority to emergency telephone calls. Typically the present invention is used in wireless local loop systems, however the present invention can also be incorporated into a conventional telephone system. The present invention uses an emergency call recognition system to determine if a person is dialing an emergency telephone number. If the emergency call recognition system recognizes a dialed telephone number as an emergency telephone number, then the caller is provided with a communication channel to complete the telephone call. The caller is provided a communication channel even if all of the communication channels are in use. This is accomplished by disconnecting calls that are not of an emergency nature.

Abstract: A method and apparatus are provided that determine a frequency dependent calibration vector for a set of transmit or receive chains of a radio communications system using only differential phase and amplitude between the transmit chains and the receive chains, respectively. In one embodiment, the invention includes an antenna array adapted to transmit and receive radio communications signals with a plurality of other terminals, a transmit chain to transmit a calibration signal through the antenna array to a transponder on at least two different frequency bands, and a receive chain to receive through the antenna array a transponder signal from the transponder, the transponder signal being received on at least two different frequency bands and being based on the calibration signal.

Abstract: A method and system for providing selective interference mitigation (or nulling) in an adaptive array system. A communication device, typically employing an adaptive array, determines an indication of signal reception quality for a first remote user terminal in communication with the communication device. The communication device provides a first mode of operation wherein a first amount of nulling with respect to at least one interfering source is generated by the communication device. In addition, the communication device provides a second mode of operation characterized by generating a second amount of nulling with respect to the at least one interfering source, wherein the second amount of nulling is relatively greater than the first amount of nulling. Based on the relative signal reception quality indication, the communication device selects one of the first and second modes of operation.

Abstract: A method and apparatus for estimating the downlink signature for a remote transceiver which is part of a wireless communication system that includes a main transceiver for communicating with the remote transceiver. The main transceiver includes an array of transmit antenna elements. The method uses the remote transceiver for receiving signals when the main transceiver transmits downlink calibration signals. When the main transceiver also has a receive antenna array, the remote transceiver can transmit uplink calibration signals to the main transceiver for determining an uplink signature. The downlink and uplink signatures are used to determine a calibration function to account for differences in the apparatus chains that include the antenna elements of the arrays, and that enable downlink smart antenna processing weights to be determined from uplink smart antenna processing weights when the main transceiver includes means for smart antenna processing according to weights.

Abstract: 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.

Abstract: A power sharing apparatus and method. In one embodiment, a method of sharing power includes switchably coupling and decoupling each of a plurality of power sources to deliver at least a portion of power to a shared power supply. Each of the power sources corresponds to one of a plurality of applications. The method also includes adjusting the portion of power delivered by each one of the power sources to the shared power supply responsive to an amount of usage by the application corresponding to the respective power source.

Abstract: A method and apparatus for predicting uplink and/or downlink beamforming in a wireless communication system employing an antenna array. The method and apparatus may predict uplink and/or downlink weights as a function of previous uplink and/or downlink weights. An interpolation of a sample of uplink weights and/or downlink weights is used to predict a future uplink or downlink weight.

Abstract: 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.

Abstract: An antenna monitor collects statistics about the received signal strengths of each antenna in a cooperating antenna array over long periods of time. In cellular telephone base station applications for a base station using an array of antenna elements to obtain spatial diversity, samples of the received signal strength are taken during particular times whenever an active mobile subscriber is operating in the area. Periodically, such samples are averaged and added to a running total that is maintained in a long-term accumulator for each antenna. The accumulated totals are then compared after a statistically sufficient number of samples have been collected and averaged. Faulty antennas, including broken ones and ones with bad connections, will be revealed by those corresponding signal paths having relatively low accumulated totals. Given long enough collection periods, the spatial diversity of the antennas in the array will have only a minimal impact on favoring one antenna over another.

Abstract: 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.