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: 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: According to an exemplary embodiment, a method with antenna selection in a communication system may support an antenna selection function at a central node having a plurality of antennas; and co-schedule multiple distributed nodes to the same resource in a downlink channel from the central node to the multiple distributed nodes by using multiple precoders related to the multiple distributed nodes to provide a system performance gain; wherein the multiple precoders are under one of conditions of partially overlapped antenna selection, non-overlapped antenna selection, and fully overlapped antenna selection.

Abstract: A method of a transient handover for performing packet offloading is disclosed. The method is used in a cellular network and includes: finding at least one qualified user equipment according to a determining method, and transmitting a handover-transient request to the qualified UE; finding and transmitting an access request to a wireless local area network after the UE receives the handover-transient request; transmitting a handover-transient ACK to a mobility management entity when the qualified user equipment accesses the wireless local area network; and releasing a bearer resource of the qualified user equipment when the MME receives the handover-transient ACK, retaining bearer information of the qualified user equipment, and handing over the qualified user equipment from the cellular network to the wireless local area network.

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: At least some reference symbols dedicated to a particular communication device are transmitted in resource blocks allocated to other devices. This way, reference symbol assignments are not unduly restricted by other constraints placed on the boundary elements of a resource block. According to an embodiment, data and reference signals are transmitted by transmitting a resource block allocated to a first communication device. The resource block includes a plurality of resource elements, each resource element corresponding to a modulation symbol. At least one reference symbol associated with the resource block and dedicated to the first communication device is transmitted in a resource block allocated to a second communication device. On the receive side, the communication device can perform channel estimation based on reference symbols dedicated to the device that are transmitted in resource blocks allocated to the device and in resource block(s) allocated to other communication device(s).

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: At least some reference symbols dedicated to a particular communication device are transmitted in resource blocks allocated to other devices. This way, reference symbol assignments are not unduly restricted by other constraints placed on the boundary elements of a resource block. According to an embodiment, data and reference signals are transmitted by transmitting a resource block allocated to a first communication device. The resource block includes a plurality of resource elements, each resource element corresponding to a modulation symbol. At least one reference symbol associated with the resource block and dedicated to the first communication device is transmitted in a resource block allocated to a second communication device. On the receive side, the communication device can perform channel estimation based on reference symbols dedicated to the device that are transmitted in resource blocks allocated to the device and in resource block(s) allocated to other communication device(s).

Abstract: A wireless communication network employs a distributed antenna system to provide radio coverage. The wireless communication network comprises a plurality of access points providing service in respective coverage areas. The access point within each coverage area connects to a plurality of antennas that are widely distributed within the coverage area. Radio resources at antennas within the overlapping region of two or more neighboring coverage areas are shared by the access points in the neighboring coverage areas according to a multiple access scheme. The sharing of radio resources within the overlapping region of two or more coverage areas allows the overlapping region to be enlarged, thereby providing more time to complete a handover.

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: 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: Inter-CoMP cell interference is reduced by “extending” at least one CoMP cell to include UEs served by a neighboring CoMP cell in the extended CoMP cell's transmission calculations, so as to minimize interference to the UEs served by other CoMP cells. Each UE in a border sub-cell identifies neighboring CoMP cells from which it receives interference in excess of a threshold value, and includes the interfering CoMP cells in a close-neighbor set. The close-neighbor set is transmitted to the UE's serving CoMP cell controller. When downlink transmissions are scheduled to the target UE, the controller notifies the neighboring CoMP cells in the close-neighbor set, identifying the target UE. Those CoMP cells then use information about the channel conditions from their transmit antennas to the target UE receive antennas to compute transmissions to UEs they serve, with the constraint that interference to the target UE is below a predetermined level.

Abstract: Systems and method are disclosed for graph-based distributed parameter coordination in a communication network. In general, discrete local parameters to be coordinated among communication nodes in the network and their respective performance metrics, or costs, are modeled using a factor graph. Based on the factor graph, a variant of the sum-product algorithm, namely the min-sum algorithm, is applied in order for the communication nodes, through iterative message passing with their neighboring communication nodes, to decide upon optimal values for the local parameters for the communication nodes that collectively optimize a global performance metric across the communication network. In one embodiment, the communication network is a wireless communication network. In one specific embodiment, the wireless communication network is a cellular communication network.

Abstract: Systems and methods are disclosed for providing energy efficient operation for wireless access nodes in a dense deployment of wireless access nodes in a cellular communication network. In one particular embodiment, wireless access nodes form a super dense network. In one embodiment, a wireless access node in a dense deployment of wireless access nodes in a cellular communication network includes a transmitter and a receiver that are operated according to a discontinuous transmit and a discontinuous receive mode of operation. The wireless access node controls one or more duty cycles for the discontinuous transmit and discontinuous receive mode of operation based on an alertness state of the wireless access node. In one embodiment, the one or more duty cycles increase as the alertness state of the wireless access node increases. In this manner, the wireless access node is operated in an energy efficient manner.

Abstract: Systems and methods are disclosed for efficient operation of wireless access nodes in a dense deployment of wireless access nodes in a cellular communication network. In general, the dense deployment of wireless access nodes includes multiple wireless access nodes in a service area. The service area is preferably, but not necessarily, a low-load service area. As used herein, a low-load service area is an area within an overall service area of the dense deployment of wireless access nodes in which all wireless access nodes are not needed to provide a desired data capacity. Overlapping radio coverage areas of the wireless access nodes in, or serving, the service area are leveraged to enable efficient operation of the wireless access nodes in the service area.

Abstract: According to exemplary embodiments of the invention, timing and frequency offset estimation is divided into two or more stages. In each stage, a different subset of the available reference symbols is selected to perform timing synchronization, frequency synchronization, or joint timing and frequency synchronization. In each non-final stage, a respective set of the reference symbols is used to perform timing synchronization or frequency synchronization in order to narrow the uncertainty window for the timing or frequency offset, and thus reduce the search space for the final stage. In the final stage, a different set of reference symbols may be used to perform joint timing and frequency synchronization over the reduced search space.

Abstract: Network-wide inter-cell interference is reduced by aggregating cells (herein, sub-cells) into Coordinated MultiPoint (CoMP) cells, each having a controller. The CoMP cells are divided into sets, similar to a frequency reuse plan. Scheduling information regarding transmissions scheduled to and from UEs in one set of CoMP cells is transmitted to controllers in sets of neighboring CoMP cells, in advance of the transmissions. Controllers in the receiving sets of CoMP cells schedule transmission to minimize both inter-sub-cell interference and interference with the set of CoMP cells that transmitted the scheduling information, and assuming no interference from other CoMP cells. They then transmit scheduling information to subsequent set(s) of CoMP cells. The order of scheduling information transmission between sets of CoMP cells may be rotated for fairness.

Abstract: A system and method to perform Full Duplex (FD) Space Division Duplex (SDD) communication using a Self-Interference Cancelling (SIC) precoder that applies different antenna phase shifts and amplitude scales to the transmitted signals to force them to be in the null space of the selected receive antennas. Thus, a wireless communication unit can place nulls at each of its receive antennas digitally at baseband for one or more frequency bands. The SIC precoder may be computed based on the self-interference channel from the transmit chain(s) to the receive chain(s). Different SIC precoders may be adaptively selected and stored digitally for different frequency bands. Subsequent single or multi-user precoder can be applied in concatenation with the SIC precoder to transmit signals to one or more users while receiving signals from one or more users simultaneously over the same frequency band.

Abstract: A distributed parameter update procedure is provided for updating parameters that do not have discrete values. When a parameter value is changed, a search is conducted of a parameter space to find a new parameter value minimizes some cost function. The cost function is derived based on the current parameter settings in neighboring nodes. The distributed parameter update procedure may simplify the search process by localizing the search of the parameter space for a new parameter value to the vicinity of the current parameter setting. In some embodiments, the search is conducted along a line of steepest descent emanating from the current parameter setting.

Abstract: The scheduling flexibility of CSI reference signals enables time and frequency synchronization using multiple non-zero CSI-RSs transmitted in the same subframe, or using CSI-RSs transmitted in the same subframe with other synchronization signals. Also, multiple synchronization signals may be scheduled in the same subframe to enable fine time and frequency synchronization without cell-specific reference signals.