Abstract: A method and system for phase shift based time of arrival (TOA) reporting in passive location ranging is herein provided. According to one embodiment, a method includes measuring, by a responder station (RSTA), a first phase shift time of arrival (PS-TOA); measuring, by an initiator station (ISTA), a second PS-TOA; reporting, by the RSTA, the first PS-TOA, reporting, by the ISTA, the second PS-TOA; broadcasting, by the RSTA, time stamps; and determining, by a passive station (PSTA), a differential distance between the PSTA and a pair of the RSTA and ISTA based on the first PS-TOA, the second PS-TOA, and the broadcast time stamps.

Abstract: A method and system for phase shift based time of arrival (TOA) reporting in passive location ranging is herein provided. According to one embodiment, a method includes measuring, by a receiver station (RSTA), a first phase shift time of arrival (PS-TOA); measuring, by an initiator station (ISTA), a second PS-TOA; reporting, by the RSTA, the first PS-TOA, reporting, by the ISTA, the second PS-TOA; broadcasting, by the RSTA, time stamps; and determining, by a passive station (PSTA), a differential distance between the PSTA and a pair of the RSTA and ISTA based on the first PS-TOA, the second PS-TOA, and the broadcast time stamps.

Abstract: A method and apparatus are provided that allows beamforming to be used on a user-specific signal together with a sector-wide pilot signal in a communication system, such as a CDMA system. In one embodiment, the invention includes transmitting a pilot signal with a wide beamwidth to a remote terminal from a first array, transmitting a first traffic signal with a narrow beamwidth directed to the remote terminal from the first array, and transmitting a second diversity traffic signal with a second narrow beamwidth directed to the remote terminal from a second array. In some examples, the invention may also include transmitting a second pilot signal from the second antenna array.

Abstract: A communication system is provided that includes signal encoding in a multiple input multiple output system. The communication system includes wireless communication networks. The communication system includes methods of encoding and transmitting symbols in a rate-1 complex symbol per second per Hertz transmission system while achieving maximum diversity. The communication further includes methods of interleaving the complex symbols such that each interleaved symbol comprises information of at least two complex symbols where the complex symbols obtain values from a rotated constellation.

Abstract: Signal encoding in a multiple input multiple output system in a wireless communication network is provided. The communication system provides a method of encoding and transmitting symbols in a rate-2 complex symbol per second per Hertz transmission system that achieves a maximum diversity of four for a four transmit antenna system and a diversity of three on a three transmit antenna system. The communication system further provides a method of interleaving the complex symbols such that each interleaved symbol comprises information of at least two complex symbols where the complex symbols obtain values from a rotated constellation.

Abstract: A method and apparatus are provided for selecting transmission parameters for multiple transmit antenna arrays. In one embodiment, the invention includes receiving a signal from a remote radio, measuring the transmit coherency of the received signal, selecting, based on the transmit coherency, whether to apply coherent combining to signals transmitted to the remote radio using each of two transmit antenna arrays to each form a beam to coherently combine with each other beam upon receipt by the remote radio, selecting, based on the transmit coherency, whether to apply transmit diversity to signals transmitted to the remote radio using each of the two transmit antenna arrays as diversity antennas.

Abstract: A method for diversity transmission and reception for channels with intersymbol interference is created. With this method one can transmit from two or more antennas in such a way that a receiver with one or more antennas can benefit from the diversity offered by the difference in channels from the transmit antennas to the receiver antenna(s). The way the transmission and reception is organized makes it relatively simple to in the receiver detect the transmitted symbols despite intersymbol interference in the channel. Due to the increased diversity experienced by the receiver the average power level required at the receiver is reduced which can be used to increase the capacity or coverage of a wireless network and/or reduce the required transmitted power.

Abstract: A method and apparatus are provided that optimizes a transmitted user-specific signal. In one embodiment, the invention includes receiving signals from a remote radio, deriving estimates of receive channels corresponding to the received signals using the received signals, deriving a model of an expected transmit channel to the remote radio based on the receive channel estimates, deriving a set of transmit parameters to be applied to an array of transmit antennas to transmit a signal to the remote radio by optimizing a transmit power criteria using the model of the expected transmit channel and constraints on the estimated quality of a signal transmitted over the expected transmit channel, and transmitting to the remote radio by applying the derived set of transmit parameters to the transmit antenna array.

Abstract: A method for diversity transmission and reception for channels with intersymbol interference is created. With this method one can transmit from two or more antennas in such a way that a receiver with one or more antennas can benefit from the diversity offered by the difference in channels from the transmit antennas to the receiver antenna(s). The way the transmission and reception is organized makes it relatively simple to in the receiver detect the transmitted symbols despite intersymbol interference in the channel. Due to the increased diversity experienced by the receiver the average power level required at the receiver is reduced which can be used to increase the capacity or coverage of a wireless network and/or reduce the required transmitted power.

Abstract: A method and apparatus are provided that corrects for differences in reception between a user-specific signal and a common signal. In one embodiment, the invention includes receiving a common pilot signal transmitted on a wide beam at a remote terminal, receiving a user-specific signal transmitted on a directed narrow beam at the remote terminal, demodulating the user-specific signal using the common pilot signal for channel estimation, estimating a phase error in the demodulated user-specific signal using known symbols in the user-specific signal, and correcting for the phase error in the demodulated user-specific signal using the phase error estimates.

Abstract: A method and apparatus are provided that allows a training and traffic signal to be compensated for phase errors without modifying a receiver. In one embodiment, the invention encompasses an external error correction circuit having a signal input to receive training and traffic channel signals from a receive chain, a signal processing circuit to compute phase corrections to at least one of the training and traffic channel signals, and a signal generator to supply a compensation signal to effect the computed correction.

Abstract: A method and apparatus are provided that allows beamforming to be used on a user-specific signal together with a sector-wide pilot signal in a communication system, such as a CDMA system. In one embodiment, the invention includes transmitting a pilot signal with a wide beamwidth to a remote terminal from a first array, transmitting a first traffic signal with a narrow beamwidth directed to the remote terminal from the first array, and transmitting a second diversity traffic signal with a second narrow beamwidth directed to the remote terminal from a second array. In some examples, the invention may also include transmitting a second pilot signal from the second antenna array.

Abstract: A method and apparatus are provided that calibrate a wideband radio communications system without causing significant interference with simultaneous users of the system. In one embodiment, the invention includes an antenna array adapted to transmit and receive radio communications signals with a plurality of other terminals the communications signals each using a particular minimum bandwidth. A transmit chain transmits a calibration signal through the antenna array to a transponder, and a receive chain receives through the antenna array a transponder signal from the transponder, the transponder signal being based on the calibration signal and having a bandwidth narrower than the minimum bandwidth. A signal processor measures characteristics of the transponder signal as received through the receive chain. These can be used to determine spatial signatures and to calibrate the transmit chain and the receive chain.

Abstract: A method and apparatus are provided that allows beamforming to be used on a user-specific signal together with a sector-wide pilot signal in a communication system, such as a CDMA system. In one embodiment, the invention includes a plurality of elements in a defined order to transmit spatially directed signals to specific receiving radio terminals, and a single element, substantially in the center of the ordering to transmit a single pilot signal simultaneously to a plurality of receiving radio terminals.

Abstract: 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.

Abstract: A method and apparatus are provided that can combine the benefits of beamforming with transmit diversity. In one embodiment, the invention includes sampling a signal received from a remote radio at elements of an antenna array, deriving spatial parameters for transmitting a signal to the remote radio from an antenna array, sampling the signal received from the remote radio at elements of at least one additional antenna array, and deriving spatial parameters for transmitting a signal to the remote radio from the at least one additional antenna array. The invention further includes generating diversity parameters for transmitting a signal to the remote radio using each antenna array as an element of a diversity array, and transmitting a signal to the remote radio using the spatial parameters and the diversity parameters.

Abstract: A method and apparatus are provided that determine group delay for a set of transmit or receive chains over a wide frequency band without causing significant interference with simultaneous users of the system. In one embodiment, the invention includes an antenna array adapted to transmit and receive radio communications signals with a plurality of other terminals, the communications signals each using a particular minimum bandwidth, a transmit chain to transmit a calibration signal through the antenna array to a transponder on at least two different frequency bands within the minimum bandwidth, 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. A signal processor determines a frequency dependent calibration vector based on the at least two frequency bands of the transponder signal as received through the receive chain.

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 apparatus are provided that allows system calibration to be incorporated into a single function that also derives transmit parameters from receive parameters in a spatial diversity system. In one embodiment, the invention includes receiving signals at an antenna array from a plurality of different locations, deriving characterizations of the spatial parameters of the received signals, receiving measurements of a plurality of different signals transmitted from the antenna array to a plurality of different locations, deriving characterizations of the spatial parameters of the transmitted signals from the received measurements, and generating a transformation function for producing transmit spatial parameters based on measurements of received signals using the receive spatial parameter characterizations and the transmit spatial parameter characterizations.

Abstract: A method for diversity transmission and reception for channels with intersymbol interference is created. With this method one can transmit from two or more antennas in such a way that a receiver with one or more antennas can benefit from the diversity offered by the difference in channels from the transmit antennas to the receiver antenna(s). The way the transmission and reception is organized makes it relatively simple to in the receiver detect the transmitted symbols despite intersymbol interference in the channel. Due to the increased diversity experienced by the receiver the average power level required at the receiver is reduced which can be used to increase the capacity or coverage of a wireless network and/or reduce the required transmitted power.