Abstract: A first channel correlation is calculated for each pair of access terminals in a population of access terminals. A particular pair of access terminals is identified from the population of access terminals based on the first channel correlations. The population of access terminals includes a first access terminal of the particular pair of access terminals, a second access terminal of the particular pair of access terminals, and at least one remaining access terminal from the population of access terminals. A second channel correlation is calculated between the first access terminal and each of the at least one remaining access terminal. A third channel correlation is calculated between the second access terminal and each of the at least one remaining access terminal. One of the first access terminal and the second access terminal is selected to drop from service based on the second channel correlations and the third channel correlations.

Abstract: A first channel correlation is calculated for each pair of access terminals in a population of access terminals. A particular pair of access terminals is identified from the population of access terminals based on the first channel correlations. The population of access terminals includes a first access terminal of the particular pair of access terminals, a second access terminal of the particular pair of access terminals, and at least one remaining access terminal from the population of access terminals. A second channel correlation is calculated between the first access terminal and each of the at least one remaining access terminal. A third channel correlation is calculated between the second access terminal and each of the at least one remaining access terminal. One of the first access terminal and the second access terminal is selected to drop from service based on the second channel correlations and the third channel correlations.

Abstract: A communication method uses a distributed cell-free network of spatially independent service antennas. According to the method, pilot sequences are allocated to a user population of access terminals by an allocation procedure that imposes local relative orthogonality of pilot sequences. Channel coefficients for access terminals are determined by measuring allocated pilot sequences as received by each of the service antennas. In embodiments of the invention, the determination of channel coefficients is performed independently and the resulting channel coefficients are locally stored at the respective service antennas. At each service antenna, a processor independently uses locally stored channel coefficients to precode forward link signals or to at least partially decode reverse link signals.

Abstract: Systems and methods for assigning pilot sequences include randomly assigning pilot sequences to a population of access terminals. A first pilot sequence assigned to a worst performing access terminal of the population of access terminals is updated to a different pilot sequence that improves performance of the worst performing access terminal. A second pilot sequence assigned to a best performing access terminal of the population of access terminals is updated to another pilot sequence that reduces performance of the best performing access terminal.

Abstract: In one aspect, a compressive sampling encoder comprises matrix determination circuitry configured to determine a particular sampling matrix selected from a codebook comprising a plurality of sampling matrices. The compressive sampling encoder further comprises sampling circuitry coupled to the matrix determination circuitry and configured to apply the particular sampling matrix to a first signal to generate a second signal, and encryption circuitry configured to receive an identifier of the particular sampling matrix and to encrypt the identifier of the particular sampling matrix. The compressive sampling encoder provides at one or more outputs thereof the second signal and the encrypted identifier of the particular sampling matrix. Other aspects include a compressive sampling decoder, compressive sampling encoding and decoding methods, and associated computer program products.

Abstract: In one embodiment, a cellular wireless communications network, such as a large-scale antenna system (LSAS) network, having multiple base stations is logically divided into overlapping, virtual, truncated networks, where each base station functions as the master of a different truncated network, and each truncated network also has one or more base stations that function as slaves to that master base station. Each master base station generates estimated slow-fading coefficients and a slow-fading post-coding (SFP) vector based only on the wireless units current located within its truncated network. In particular, to generate the SFP vector, the master collects estimated slow-fading coefficients and estimated uplink data symbols from its slaves. The master uses the SFP vector to update its own estimated uplink data symbols for the wireless units currently located within its own cell.

Abstract: In exemplary LSAS (large-scale antenna system) networks, uplink signals are processed to compensate for pilot contamination. Slow-fading coefficients are generated for terminals in the wireless network, and postcoding matrices are generated based on the slow-fading coefficients and terminal transmit power levels. Uplink signals are received from the terminals, and M-dimensional postcoding is performed to generate estimated uplink signals from the received uplink signals, where M is the number of antennas at a base station of the wireless network. The postcoding matrices are applied to the estimated uplink signals to compensate for pilot contamination. The improved technique used to generate postcoding matrices depends on whether the M-dimensional postcoding involves matched filtering or zero forcing.

Abstract: Systems and methods for assigning pilot sequences include randomly assigning pilot sequences to a population of access terminals. A first pilot sequence assigned to a worst performing access terminal of the population of access terminals is updated to a different pilot sequence that improves performance of the worst performing access terminal. A second pilot sequence assigned to a best performing access terminal of the population of access terminals is updated to another pilot sequence that reduces performance of the best performing access terminal.

Abstract: Systems and methods for communicating data over a dual-tier wireless communication system are provided. A dual-tier wireless communication system comprises an upper tier cell-free large-scale antenna system including a plurality of service-antennas distributed in a designated coverage area for providing wireless access service to mobile terminals, and a lower tier of one or more concentrated large-scale antenna system arrays arranged within a plurality of cells of the designated coverage area for providing backhaul service to the plurality of service-antennas. The upper tier and the lower tier operate in disjoint frequency bands with respect to each other.

Abstract: Methods and apparatuses for slow-fading precoding for multi-cell wireless systems are provided. At a base station of a cellular network in which a plurality of terminals are served, the base station serving pluralities of same-cell terminals and neighboring-cell terminals, and the cellular network including neighboring-cell base stations that serve respective pluralities of same-cell terminals and neighboring-cell terminals, a same-cell and one or more neighboring cells within the cellular network are selected, the same-cell and one or more neighboring cells comprising a truncated network.

Abstract: In exemplary LSAS (large-scale antenna system) networks, uplink signals are processed to compensate for pilot contamination. Slow-fading coefficients are generated for terminals in the wireless network, and postcoding matrices are generated based on the slow-fading coefficients and terminal transmit power levels. Uplink signals are received from the terminals, and M-dimensional postcoding is performed to generate estimated uplink signals from the received uplink signals, where M is the number of antennas at a base station of the wireless network. The postcoding matrices are applied to the estimated uplink signals to compensate for pilot contamination. The improved technique used to generate postcoding matrices depends on whether the M-dimensional postcoding involves matched filtering or zero forcing.

Abstract: A new method is disclosed for providing wireless fixed access from an array of service antennas to a population of local terminals. In implementations, a service transceiver station (STS) performs beamform precoding using channel state information (CSI) obtained from transmissions by the local terminals, and the STS performs power allocation using slow fading coefficients which are static over the service antenna positions and over a frequency range spanning at least some carriers used for downlink transmission.

Abstract: In one embodiment, a cellular wireless communications network, such as a large-scale antenna system (LSAS) network, having multiple base stations is logically divided into overlapping, virtual, truncated networks, where each base station functions as the master of a different truncated network, and each truncated network also has one or more base stations that function as slaves to that master base station. Each master base station generates estimated slow-fading coefficients and a slow-fading post-coding (SFP) vector based only on the wireless units current located within its truncated network. In particular, to generate the SFP vector, the master collects estimated slow-fading coefficients and estimated uplink data symbols from its slaves. The master uses the SFP vector to update its own estimated uplink data symbols for the wireless units currently located within its own cell.

Abstract: A method is provided, in which a base station allocates pilot signals to mobile terminals in a cell, obtains CSI from uplink pilot signals transmitted by mobile terminals, uses the CSI to precode messages, and transmits the messages in conformance with a TDD protocol. The CSI is obtained by comparing the pilot signal received from each mobile terminal to a known pilot signal associated with that mobile terminal. The known pilot signals are associated with respective mobile terminals according to a pilot signal reuse pattern in which adjacent cells are allocated mutually orthogonal reuse groups of mutually orthogonal pilot signals, and mobile terminals within a given cell are limited to transmitting only pilot signals allocated to that cell.

Abstract: A method and apparatus for communication between a wireless base station and a population of one or more terminals are provided, involving, in each of a plurality of iterations, transmitting a block of forward-link data from an array of multiple base station antennas to the terminal population. In each iteration, a forward-link power level is updated for each said terminal using a distributed algorithm and purely local information. Meanwhile, a set of beamforming coefficients based on channel state information (CSI) obtained from reverse-link pilot signals is periodically updated, and each data block is precoded with the most recently updated beamforming coefficients. Each data block is transmitted at the most recently updated forward-link power levels.

Abstract: A large-scale antenna system (LSAS) base station transmits one or more first signals on one or more first channels corresponding to one or more first access terminals associated with the LSAS base station concurrently with nulling one or more second channels corresponding to one or more second access terminals associated with one or more small cells. The first signal(s) is/are transmitted synchronously with the second signal(s) transmitted by the small cell(s).

Abstract: Methods and apparatuses for slow-fading precoding for multi-cell wireless systems are provided. At a base station of a cellular network in which a plurality of terminals are served, the base station serving pluralities of same-cell terminals and neighboring-cell terminals, and the cellular network including neighboring-cell base stations that serve respective pluralities of same-cell terminals and neighboring-cell terminals, a same-cell and one or more neighboring cells within the cellular network are selected, the same-cell and one or more neighboring cells comprising a truncated network.

Abstract: Systems and methods for communicating data over a dual-tier wireless communication system are provided. A dual-tier wireless communication system comprises an upper tier cell-free large-scale antenna system including a plurality of service-antennas distributed in a designated coverage area for providing wireless access service to mobile terminals, and a lower tier of one or more concentrated large-scale antenna system arrays arranged within a plurality of cells of the designated coverage area for providing backhaul service to the plurality of service-antennas. The upper tier and the lower tier operate in disjoint frequency bands with respect to each other.

Abstract: Embodiments of methods and apparatuses for characterizing an electrical power distribution system are disclosed. One method includes applying a plurality of test signals to a first plurality of test points of the electrical power distribution system, measuring a plurality of response signals at a second plurality of test points of the electrical distribution system, deriving a characterization matrix for the electrical power distribution system from the plurality of test signals and response signals, and characterizing the electrical power distribution system based on the derived characterization matrix.

Abstract: Methods and apparatuses for slow-fading precoding for multi-cell wireless systems are provided. At a base station of a cellular network, the base station serving a pluralities of same-cell terminals and other-cell terminals, and the cellular network including other base stations that serve respective pluralities of same-cell terminals and other-cell terminals, a plurality of slow-fading coefficients are obtained, wherein each of the plurality of slow-fading coefficients is associated with channel state information for communication between one of the other base stations and one of the respective same-cell terminals or other-cell terminals. A set of slow-fading precoding coefficients are generated for transmitting signals to same-cell terminals and other-cell terminals based on the plurality of slow-fading coefficients.