Abstract: Wireless communication techniques are disclosed. These techniques include a plurality of base stations, each of the plurality of bases stations operating in a respective area and communicating with one or more mobile stations in the respective area using a primary communication technique. One or more of the plurality of base stations are configured to communicate with a backhaul using an ad-hoc radio frequency link with another of the plurality of base stations. The ad-hoc radio frequency link utilizes an independent radio and frequency band from the primary communication technique with which the respective base station communicates with mobile stations.

Abstract: A receiver detects a plurality of information symbols. A first signal and a second signal are received from a first transmitted signal and a second transmitted signal, respectively, transmitted by a first plurality of antennas and received by a second plurality of antennas connected to the receiver. The second signal is received after the first signal. The receiver spatially filters the first signal using a spatial filter matrix. The receiver computes a conjugate of the first filtered signal to define a conjugate first signal, and spatially filters a second signal using the spatial filter matrix. The receiver computes a Hadamard product of the first filtered signal and the conjugate first signal to define a differential measurement signal. The receiver detects the plurality of information symbols from the differential measurement signal.

Abstract: A receiver detects a plurality of information symbols. A first signal and a second signal are received from a first transmitted signal and a second transmitted signal, respectively, transmitted by a first plurality of antennas and received by a second plurality of antennas connected to the receiver. The second signal is received after the first signal. The receiver spatially filters the first signal using a spatial filter matrix. The receiver computes a conjugate of the first filtered signal to define a conjugate first signal, and spatially filters a second signal using the spatial filter matrix. The receiver computes a Hadamard product of the first filtered signal and the conjugate first signal to define a differential measurement signal. The receiver detects the plurality of information symbols from the differential measurement signal.

Abstract: A method of estimating a spatial filter matrix is provided. A conjugate of a received first signal defines a conjugate first signal. A Kronecker product of the defined first signal and a received second signal define a differential measurement signal. The computations are repeated for a plurality of first and second signals sufficient to compute an estimate of a channel matrix from the differential measurement signals. A spatial filter matrix is computed from the computed estimate of the channel matrix. The computed spatial filter matrix is used in a data communication phase between the first plurality of antennas and the second plurality of antennas.

Abstract: A method of estimating a spatial filter matrix is provided. A conjugate of a received first signal defines a conjugate first signal. A Kronecker product of the defined first signal and a received second signal define a differential measurement signal. The computations are repeated for a plurality of first and second signals sufficient to compute an estimate of a channel matrix from the differential measurement signals. A spatial filter matrix is computed from the computed estimate of the channel matrix. The computed spatial filter matrix is used in a data communication phase between the first plurality of antennas and the second plurality of antennas.

Abstract: Beam measurement values are computed by transforming a signal to a beamspace representation using a beamforming matrix that includes a plurality of columns that define a plurality of beams. A second plurality of beams is selected from the plurality of beams based on a power captured by each beam derived from the computed beam measurement values. For each beam of the second plurality of beams as a first beam, a spatial phase shift component and a temporal delay component is computed based on the fixed spatial angle associated with the first beam and a carrier frequency, a filter is defined using the spatial phase shift component and the temporal delay component, a beam measurement value associated with the first beam from the computed beam measurement values is selected, and the defined filter is applied to the selected beam measurement value to define a filtered value.

Abstract: Beam measurement values are computed by transforming a signal to a beamspace representation using a beamforming matrix that includes a plurality of columns that define a plurality of beams. A second plurality of beams is selected from the plurality of beams based on a power captured by each beam derived from the computed beam measurement values. For each beam of the second plurality of beams as a first beam, a spatial phase shift component and a temporal delay component is computed based on the fixed spatial angle associated with the first beam and a carrier frequency, a filter is defined using the spatial phase shift component and the temporal delay component, a beam measurement value associated with the first beam from the computed beam measurement values is selected, and the defined filter is applied to the selected beam measurement value to define a filtered value.

Abstract: A transmitter supporting multiple-input, multiple-output communications is provided. The transmitter includes a signal processor, a plurality of feed elements, and an aperture. The signal processor is configured to simultaneously receive a plurality of digital data streams and to transform the received plurality of digital data streams into a plurality of analog signals. The number of the plurality of digital data streams is selected for transmission to a single receive antenna based on a determined transmission environment. The plurality of feed elements are configured to receive the plurality of analog signals, and in response, to radiate a plurality of radio waves toward the aperture. The aperture is configured to receive the radiated plurality of radio waves, and in response, to radiate a second plurality of radio waves toward the single receive antenna.

Abstract: A transmitter supporting multiple-input, multiple-output communications is provided. The transmitter includes a signal processor, a plurality of feed elements, and an aperture. The signal processor is configured to simultaneously receive a plurality of digital data streams and to transform the received plurality of digital data streams into a plurality of analog signals. The number of the plurality of digital data streams is selected for transmission to a single receive antenna based on a determined transmission environment. The plurality of feed elements are configured to receive the plurality of analog signals, and in response, to radiate a plurality of radio waves toward the aperture. The aperture is configured to receive the radiated plurality of radio waves, and in response, to radiate a second plurality of radio waves toward the single receive antenna.

Abstract: A wireless communication system supporting improved performance in a sparse multi-path environment is provided that uses spatially reconfigurable arrays. The system includes a first device and a second device. The first device includes a plurality of antennas and a processor operably coupled to the plurality of antennas. The plurality of antennas are adapted to transmit a first signal toward a the second device and to receive a second signal from the second device. The processor is configured to determine an antenna spacing between the plurality of antennas based on an estimated number of spatial degrees of freedom and an estimated operating signal-to-noise ratio. The second device includes a receiver adapted to receive the first signal from the first device, a transmitter adapted to transmit the second signal toward the first device, and a processor. The processor estimates the number of spatial degrees of freedom and the operating signal-to-noise ratio from the received first signal.

Abstract: A system supporting data retrieval from a plurality of wireless sensor nodes is defined. The system includes the plurality of wireless sensor nodes and a data retrieval device. The plurality of wireless sensor nodes include a transceiver receiving a first signal and transmitting a second signal. The second signal includes a sensed datum or an encoded statistic based on the sensed datum identified at the plurality of wireless sensor nodes. The data retrieval device includes a plurality of antennas transmitting the first signal toward the plurality of wireless sensor nodes and receiving the second signal from the plurality of wireless sensor nodes, and a processor coupled to receive the received second signal from the plurality of antennas, the processor defining a virtual receive signal from the received second signal for the plurality of antennas and processing the defined virtual receive signal to determine the identified sensed datum.

Abstract: A wireless communication system supporting improved performance in a sparse multi-path environment is provided that uses spatially reconfigurable arrays. The system includes a first device and a second device. The first device includes a plurality of antennas and a processor operably coupled to the plurality of antennas. The plurality of antennas are adapted to transmit a first signal toward a the second device and to receive a second signal from the second device. The processor is configured to determine an antenna spacing between the plurality of antennas based on an estimated number of spatial degrees of freedom and an estimated operating signal-to-noise ratio. The second device includes a receiver adapted to receive the first signal from the first device, a transmitter adapted to transmit the second signal toward the first device, and a processor. The processor estimates the number of spatial degrees of freedom and the operating signal-to-noise ratio from the received first signal.