Abstract: The present invention provides method and apparatus for facilitating base station selection/handover by a user terminal in a distributed (e.g., cellular-type) wireless communication system. In accordance with one aspect, hysteresis is adaptively determined as a function of the variance of receive signal strength fluctuations. In turn, an adaptive hysteresis factor can be obtained and used for a subsequent handover decision, for example, based on a cost function that takes into account the hysteresis. In accordance with another aspect, base station selection depends on a number of criteria, such as received signal strength, base station load, and estimated distance between a receiving user terminal and one or more base stations.

Abstract: Embodiments of the present invention provide methods and apparatuses for determining a parameter value for each of a plurality of communication signals received concurrently as a composite signal. The parameter value of each communication signal is within a corresponding parameter value set. Each parameter value set is disjoint from every other parameter value set. The parameter value for a particular communication signal is estimated by searching over the parameter value set corresponding to the particular communication signal. For one embodiment, the composite signal is received at a base station receiver of a SMDA/TMDA system that includes an array of spatially distributed antenna elements. To recover multiple communication signals at once, an embodiment of the invention segments the timing search window into disjoint intervals and invokes an instance of a basic receiver module for each timing search window.

Abstract: According to an embodiment of the invention, a method and apparatus are described to receive a signal, determine a quality of the received signal, and transmit a power control message, with a selected size, to request a modification in transmission power, the power control message being based at least in part on the quality of the received signal.

Abstract: According to an embodiment of the invention, a method and apparatus are described to receive a signal, determine a quality of the received signal, and transmit a power control message, with a selected size, the power control message being based at least in part on the quality of the received signal. The power control message requests a modification in transmission power or indicates the deviation of the signal quality from a reference signal quality.

Abstract: Payload reconstructing methods and apparatuses from wideband signals in the presence of multipath channel imperfections and frequency offset are disclosed. In one embodiment, a method in accordance with the teachings of the present invention includes receiving a signal, estimating a frequency offset of the received signal, performing frequency offset compensation on the received signal in response to the estimated frequency offset, performing equalization compensation on the received signal in response to the frequency offset compensated signal, and outputting payload information included in the received signal in response to the equalized frequency compensated received signal.

Abstract: The present invention provides method and apparatus for facilitating base station selection/handover by a user terminal in a distributed (e.g., cellular-type) wireless communication system. In accordance with one aspect, hysteresis is adaptively determined as a function of the variance of receive signal strength fluctuations. In turn, an adaptive hysteresis factor can be obtained and used for a subsequent handover decision, for example, based on a cost function that takes into account the hysteresis. In accordance with another aspect, base station selection depends on a number of criteria, such as received signal strength, base station load, and estimated distance between a receiving user terminal and one or more base stations.

Abstract: An apparatus and method for adaptively producing transmitted signals and processing received signals in a communication system which includes smart antenna array of antenna elements. When processing received signals, the invention modifies an existing processing scheme by incorporating information about a second set of signals for which training or other characteristic information such as a reference is unknown to information about a first set of signals for which characteristic information such as a reference is known, prior to executing the processing scheme. This approach can be used to modify the receive weights which determine the relative weight assigned to the signals received from each of a plurality of antenna elements to take into account the presence of a changing interference environment.

Abstract: 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.

Abstract: The present invention provides method and apparatus for facilitating base station selection/handover by a user terminal in a distributed (e.g., cellular-type) wireless communication system. In accordance with one aspect, hysteresis is adaptively determined as a function of the variance of receive signal strength fluctuations. In turn, an adaptive hysteresis factor can be obtained and used for a subsequent handover decision, for example, based on a cost function that takes into account the hysteresis. In accordance with another aspect, base station selection depends on a number of criteria, such as received signal strength, base station load, and estimated distance between a receiving user terminal and one or more base stations.

Abstract: The present invention provides method and apparatus for facilitating base station selection/handover by a user terminal in a distributed (e.g., cellular-type) wireless communication system. In accordance with one aspect, hysteresis is adaptively determined as a function of the variance of receive signal strength fluctuations. In turn, an adaptive hysteresis factor can be obtained and used for a subsequent handover decision, for example, based on a cost function that takes into account the hysteresis. In accordance with another aspect, base station selection depends on a number of criteria, such as received signal strength, base station load, and estimated distance between a receiving user terminal and one or more base stations.

Abstract: In one embodiment of the present invention, a receiver can only properly receive signals that were intended for the receiver because the data descrambling depends on the identity of the receiver. In one embodiment, the invention is a communication device including a data source containing data to be transmitted to a remote radio, and a randomizer to scramble the data using an identifier related to the remote radio. In one embodiment, at least a part of the identifier related to the remote radio is used as at least part of a seed of the randomizer.

Abstract: According to an embodiment of the invention, a method and apparatus are described for transmission link adaptation. In one embodiment of the invention, data is obtained regarding a quality of a transmitted signal. Data is obtained regarding available power for transmission. A transmission mode is selected based at least in part on the quality of the transmitted signal and on the available power for transmission.

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: According to an embodiment of the invention, a method and apparatus are described to receive a signal, determine a quality of the received signal, and transmit a power control message, with a selected size, the power control message being based at least in part on the quality of the received signal. The power control message requests a modification in transmission power or indicates the deviation of the signal quality from a reference signal quality.

Abstract: According to an embodiment of the invention, a method and apparatus are described to receive a signal, determine a quality of the received signal, and transmit a power control message, with a selected size, to request a modification in transmission power, the power control message being based at least in part on the quality of the received signal.

Abstract: The present invention can be used to perform training using secondary data. In one embodiment the present invention includes receiving a communications signal of a communications channel, where the communications signal has a primary and a secondary data segment both communicating information, and determining a parameter of the communications channel using the secondary data segment. In another embodiment of the present invention, the communications signal can also include a training segment containing a known training signal.

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: In one embodiment, the present invention includes a repeating frame for a time division radio communications system with a sequence of uplink slots each having a predetermined duration, a sequence of downlink slots, each having a predetermined duration that is greater than the duration of the uplink slots, an interburst guard time between each uplink slot, an interburst guard time between each downlink slot, and an interframe guard time after the sequence of downlink slots.

Abstract: In one embodiment, the present invention includes a slot in a repeating time division frame with a first training sequence, an information sequence after the first training sequence, and a second training sequence after the information sequence. In some embodiments either the first or the second training sequences indicates a type for the information sequence, such as a random access channel message and a traffic channel message, a configuration message, a channel assignment message, or a data traffic message.

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.