Abstract: Compressive sampling is used to generate pilot symbols to be transmitted over an array of antennas in a MIMO wireless communications device. A pilot symbol is transmitted over the array of antennas according to a spatially randomized antenna transmission function that randomly changes across the array of antennas. The randomized antenna transmission function may randomly select/deselect antennas and/or randomly change amplitude and/or phase of the pilot symbol transmission. Channel estimates can be constructed at a receiver based on the spatially randomized pilot symbols that were transmitted.

Abstract: A system comprises a communication device that chooses a parameter setting from a set of available parameter settings. The system may include multiple communication devices, and each available parameter setting may have an associated cost. The communication device may receive parameter setting information from one or more other communication devices in the system, and the parameter setting information may identify the parameter setting being used by the one or more communication devices in the system. The communication device may choose a parameter setting that is associated with the lowest cost based on the parameter setting information received from the one or more other communication devices in the system.

Abstract: A method and apparatus for channel estimation based on extracting channel information, including noise spectral density, from a received signal, and advantageously exploiting that information for improved channel estimation accuracy. One embodiment is directed to a method of generating channel estimates in a wireless communication receiver, for processing a received communication signal. The method includes generating first channel estimates from a set of pilot observations obtained from the received communication signal, using a first channel estimation process that is not dependent on knowledge of channel statistics. The method further includes estimating channel statistics and a noise variance from the first channel estimates, and generating second channel estimates from the set of pilot observations, the estimated channel statistics, and the estimated noise variance, using a second channel estimation process that is dependent on knowledge of the channel statistics.

Abstract: A group of multiple base stations implements distributed and coordinated antenna beamforming selection to achieve increased performance. Each of the base stations in the group determines an associated optimal set of antenna beam direction parameters in a distributed manner based on local radio information exchanged between neighboring ones of the base stations. Each of the base stations transmits to one or more user equipments (UEs) served by that base station using its associated optimal set of beam direction parameters. The local radio information generated by one of the base stations indicates how the transmissions of its neighbor base stations affect the performance of the base station. The performance of a base station may be measured by the difficulty or challenge in maintaining a minimum desired signal quality, e.g., a minimum SINR, for the UE served by the base station.

Abstract: A Coordinated Multipoint (CoMP) controller advantageously reduces the transmit powers of transmissions coordinated across a plurality of sub-cells within a CoMP cell. The CoMP controller determines serving sub-cell path gains and interfering sub-cell path gains for a set of mobile terminals to be served by distinct sub-cells. The CoMP controller then evaluates an objective function that expresses an aggregate throughput of concurrent transmissions to be sent to or received from the set of mobile terminals as a function of the serving sub-cell path gains, the interfering sub-cell path gains, and the individual transmit powers of those transmissions, to determine the combination of individual transmit powers that maximizes the aggregate throughput while meeting minimum quality of service requirements for the mobile terminals. The combination of individual transmit powers will necessarily require less power than if the concurrent transmissions were each sent at maximum transmit power.

Abstract: Transmitted signals are modified to facilitate the emulation of circular convolution in non-contiguous transmission environments. These modified signals may be derived from well-known signature sequences. In an exemplary method, a tail portion of a final segment of a base signal is prefixed to an initial segment of the base signal, to form a first transmit segment. One or more additional transmit segments are formed by prefixing, to each of the one or more segments of the base signal other than the initial segment, a tail portion of the immediately preceding segment of the base signal. The transmit segments so formed are transmitted in respective ones of the plurality of non-contiguous transmit-time intervals. Corresponding methods for receiving the transmitted segments and reconstructing the base signal are also described, as are corresponding transmitting and receiving apparatuses.

Abstract: A transmitter, receiver, and method for channel estimation for a Multiple-Input Multiple-Output (MIMO) communication system in which the transmitter includes a multiplicity of transmit antennas spaced such that spacing between adjacent antennas provides a spatial correlation coefficient greater than a threshold level. The transmitter selects a subset of the multiplicity of transmit antennas for transmitting the pilot reference signals. The pilot reference signals are transmitted only from the selected subset of transmit antennas to the receiver. The receiver includes a channel estimator configured to derive a channel estimation for all of the multiplicity of transmit antennas using the received pilot reference signals and known or estimated spatial correlation among the multiplicity of transmit antennas.

Abstract: A signature sequence is employed in a wireless transmission over a channel and is detected by a receiving station. The signature sequence is selected from a subset of sequences chosen from a set of sequences formed by delay-Doppler shifts of a base sequence. Use of the subset of sequences simplifies detection of the signature sequence by, e.g., facilitating use of a simpler detector structure. A subset of N2 sequences of the specially-constructed delay-Doppler shifted sequence set is selected to facilitate more efficient computation of the detection metric. A simplified detector employs algebraic techniques (such as Discrete Fourier 'Transform (DFT)) that exploit prudent sequence assignment strategy. As an advantageous variation, for a particular class of base sequences that can be represented by segments of equal-length sinusoids, even greater complexity reduction can be achieved by segmenting the delay-Doppler correlation accordingly and reusing past outcome in subsequent overlapping segments.

Abstract: A signature sequence employed in a wireless transmission over a channel is detected and utilized. The signature sequence is selected from a set of sequences formed by delay-Doppler shifts of a base sequence. Preferably but not exclusively, the set of sequences is formed by circular delay-Doppler shifts of the base sequence. The base sequence can be, for example, an m-sequence. A received signal is obtained from a received wireless transmission. A candidate sequence selector (90) selects a candidate sequence from among a set of sequences for evaluation as the signature sequence, the set of sequences having been formed by sequence set generator (88) as delay-Doppler shifts of a base sequence. An image former (82) uses the base sequence and the received signal to form a delay-Doppler image with respect to an image area pertinent to the candidate sequence.

Abstract: The present invention relates to a method for detecting a pilot pattern, comprising a pilot signal sp(t), in a received signal r(t) implemented in an Orthogonal Frequency Division Multiplexing (OFDM) system. The method comprises the steps: computing a value of a log-likelihood function (?0,?0) for a hypotheses space specified by the pilot signal sp(t) and an initial time frequency offset (?0,?0), and relating the computed value to a reference value to detect the pilot pattern.

Abstract: A compression/decompression method for backhaul communication of a complex-valued radio signal between base stations and the network processing unit, such as a Central Processor of a Coordinated MultiPoint (CoMP) system, significantly reduces backhaul bandwidth. The spatial and temporal correlations of the wireless IQ signal are exploited in order to remove redundancy and substantially reduce signal bandwidth. Feature component signals of significance are extracted through linear transformation to form the radio signal, and are individually quantized, possibly at different bit rates in accordance with their relative importance. The transformation can either be pre-determined or computed in real-time based on the spatial and temporal statistics of the radio signal. In the latter case, the transformation matrix or matrices are also sent over the backhaul in order to allow the radio signal to be reconstructed at the receiving end. Different methods of generating the transformation matrices are proposed.

Abstract: An apparatus, system, and method for dynamic, distributed coordination of parameters between a plurality of base stations in a cellular telecommunication network. An inter-cell communication interface connecting each given base station with the given base station's neighboring base stations is extended to communicate parameter settings between the given base station and the neighboring base stations. An apparatus in each given base station receives from the given base station's neighboring base stations, parameter settings being utilized by the neighboring base stations for transmitting and/or receiving in associated neighboring cells. The apparatus utilizes the parameter settings received from the neighboring base stations as factors to determine local parameter settings for the given base station. The given base station then sends the local parameter settings and supplemental information to the neighboring base stations so that optimal network-wide parameter settings can be selected.

Abstract: Transmitted signals are modified to facilitate the emulation of circular convolution in non-contiguous transmission environments. These modified signals may be derived from well-known signature sequences. In an exemplary method, a tail portion of a final segment of a base signal is prefixed to an initial segment of the base signal, to form a first transmit segment. One or more additional transmit segments are formed by prefixing, to each of the one or more segments of the base signal other than the initial segment, a tail portion of the immediately preceding segment of the base signal. The transmit segments so formed are transmitted in respective ones of the plurality of non-contiguous transmit-time intervals. Corresponding methods for receiving the transmitted segments and reconstructing the base signal are also described, as are corresponding transmitting and receiving apparatuses.

Abstract: A system for managing radio access resources includes a joint radio resource management/transport resource management unit configured to communicate with a plurality of radio units over a transport network, to jointly allocate radio resources at the radio unit and transport resources on the transport network in response to requests from wireless terminals requesting access to radio resources from the radio units, to send a radio resource allocation schedule to the plurality of radio units that defines radio resource allocations for the wireless terminals, and to generate a transport resource allocation schedule that defines transport resource allocations for the wireless terminals. The system further includes a transport resource controller configured to receive the transport resource allocation schedule and to map user data to physical transport resources on the transport network in response to the transport resource allocation schedule.

Abstract: A large scale, self-calibrating multi-antenna wireless communication system calibrates the transmit-receive RF chains of antennas in the system. The system, during a first time interval, transmits a pilot signal from at least those antennas in a first time-reuse group, so that the pilot signals are received at antennas in one or more other time-reuse groups. The system, during a second time interval, transmits a pilot signal from at least those antennas in a second time-reuse group, so that the pilot signals are received at antennas in one or more other time-reuse groups. The system also, during a third time interval, transmits a pilot signal from at least those antennas in a third time-reuse group, so that the pilot signals are received at antennas in one or more other time-reuse groups. Based on these received pilot signals, the system calculates RF-chain calibration factors for one or more of the antennas.

Abstract: The amount of multi-antenna signals to be transmitted over the backhaul in a Coordinated MultiPoint (CoMP) system from the central processor (CP) to each base station is reduced. Embodiments of the present invention exploit characteristics of the underlying signal structure, and distribute some baseband processing functionalities—such as channel coding and the application of the multi-user precoding—from the CP to the remote base stations. Additionally, in some embodiments the non-precoded parts of multi-antenna signals are broadcast from the CP to all base stations in the CoMP system, to further reduce the burden on backhaul communications. In one embodiment, the backhaul network is a Gigabit-capable Passive Optical Network (GPON).

Abstract: An apparatus (20) is associated with a telecommunications node (N) which serves a service area (S) which belongs to one set of plural sets of service areas comprising a network. The apparatus (20) divides a time resource for the node into plural phases in coordinated manner with other service areas. The apparatus (20) further generates a schedule for transmission/reception of user traffic for wireless terminals served by the node for plural consecutive phases. The schedule is generated so that during the plural consecutive phases the node can transmit and receive scheduled user traffic before receiving in the plural consecutive phases scheduling information from another node which serves another set of service areas.

Abstract: The present invention relates to a method and arrangement for reducing feedback data in a communication system, said communication system comprising a number of transmitter antennas, n?, and a number of receiver antennas, nR, for parallel spatially independent transmission and reception of signals, wherein a channel response is represented by a matrix (G) containing nR×n? complex variables. The method comprises the steps of: decomposing an expression of said channel response matrix (G) into products of a unitary transform (V), nR×nT diagonal matrix (?) and a conjugate transpose of a unitary matrix (W). Choosing said unitary matrix (W) such that its diagonal elements are real, substituting said channel response matrix (G) with a representative subset of elements in said decomposed expression of said channel response matrix (G), said representative subset comprising diagonal of a first matrix (?) and lower triangle of a second matrix (W) excluding the diagonal.

Abstract: A method and controller for reducing inter-cell interference within a Coordinated Multi-Point (CoMP) cellular network architecture. Multiple CoMP cells in the network architecture are grouped into a number of mutually exclusive subsets. The CoMP cells in each subset are sufficiently separated from each other geographically so that no inter-cell interference occurs among them, and thus they can be scheduled independently. Each subset then takes turn scheduling in a certain order. As each subset schedules its transmissions, it avoids causing interference to subsets that have already scheduled, and then passes sufficient information to the remaining subsets so that the same interference avoidance measures can be taken. The scheduling and passing of the information is preferably performed before the data transmission phase, which occurs once every Transmission Time Interval (TTI).

Abstract: Smaller patterns of regularly-spaced pilot symbols are discerned from a larger pattern of irregularly-spaced pilot symbols transmitted in the time-frequency domain. Accordingly, the irregularly-spaced pilot symbols can be partitioned into at least two different groups of regularly-spaced pilot symbols in the time-frequency domain. Each group of regularly-spaced pilot symbols is individually processed with lower complexity and the results combined to generate an accurate time-frequency channel response estimate. According to an embodiment, a set of irregularly-spaced pilot symbols is transmitted over a time-frequency window. Channel response is estimated based on the pilot symbols by grouping the pilot symbols into subsets of regularly-spaced pilot symbols. An intermediate quantity is generated for each subset of regularly-spaced pilot symbols as a function of the pilot symbols included in the subset. The channel response is estimated over the time-frequency window as a function of the intermediate quantities.