Abstract: Embodiments recognize that in MIMO and M-MIMO systems, physical antennas tend to be closely spaced to each other (e.g., a grid). As a result, a spatial correlation typically exists between physical antennas as well as between transmissions from logical antenna ports. Embodiments exploit this characteristic to reduce the amount of pilot signaling needed to enable downlink channel estimation. Specifically, embodiments limit pilot signaling to only a subset of supported logical antenna ports and rely on spatial correlation information to interpolate channels from logic antenna ports for which no pilot signaling is used.

Abstract: Embodiments provide systems and methods for enabling a first transceiver to learn beamforming weights (e.g., Eigen beamforming weights) to a second transceiver, without any pilot signaling or explicit beamforming weight signaling from the second transceiver. In another embodiment, beamforming weight vectors to enable a multi-symbol spatial rate can be learned by the first transceiver.

Abstract: In wireless operating environments, wireless user devices are often within the coverage area of multiple base stations. The base station providing the best uplink for the user device may be different than the base station providing the best downlink for the user device. Systems and techniques for asymmetric uplink and downlink communications for a user device are provided. In embodiments, the user device initially synchronizes with a base station. Both the uplink and downlink are initially served by this base station. A determination is then made whether to handoff the downlink for the user device to another base station. When a determination is indicated, the downlink is handed off to the second base station. Thereafter, periodic measurements are made. The determinations whether to handoff the uplink and downlink for the user device are made independently.

Abstract: As wireless networks evolve, network providers may utilize legacy LTE devices as well as devices that support massive multi-input, multiple output (M-MIMO). Systems and methods for simultaneously servicing legacy LTE devices and M-MIMO devices are provided. In embodiments, a transmission zone for M-MIMO communications is defined within a legacy, non M-MIMO radio frame. The location of the M-MIMO transmission zone is transmitted to user devices. For example, an identification of the location of the M-MIMO transmission zone is transmitted in a system information message. In a further example, the location of the M-MIMO transmission zone is transmitted in the downlink control information. The location of the M-MIMO transmission zone may be defined dynamically based on a variety of criteria. In addition or alternatively, a set of pre-defined transmission zones may be utilized.

Abstract: In an embodiment, a method of channel estimation is provided. The method includes determining a parametric model for a channel between a first transceiver and a second transceiver and transmitting a pilot signal to the second transceiver. The receiving transceiver is configured to determine a parameter of the parametric model based at least on the pilot signal and to estimate a channel transfer function coefficient for the channel based on the parameter and the parametric model.

Abstract: A multiple input multiple output (MIMO) antenna system is implemented for communications in a wireless device. MIMO beamforming techniques are utilized to improve communications, and may be utilized in full-duplex mode. Techniques include the formation of beamforming patterns having orthogonal polarizations to one another at each communication device, but having matching polarization between transmit/receive pairs located at each respective communication device. Techniques also include the formation of beamforming patterns in a direction towards another communication device to maximize transmit power in that direction while inducing nulls in the beamforming pattern to reduce self-interference coupling via antennas configured for reception. Full-duplex communications are improved through monitoring of the self-interference coupling and adapting the beamforming patterns to reduce it.

Abstract: A multiple input multiple output (MIMO) antenna system is implemented for communications in a wireless device. Information regarding the environment surrounding the wireless device may be used to determine which of the MIMO antennas are selected such that communications performance is improved. Metrics related to signal transmission and reception by the wireless device may be monitored and used to determine which MIMO antennas are selected. The metrics may be measured by any of the MIMO antennas at any time, including antennas currently engaged or not engaged in active communications. The metrics may be used in lieu of sensors to supplement or replace wireless device functionality otherwise provided by the sensors.

Abstract: Systems and methods are provided for efficient tree-based detection of multi-carrier modulated signals, such as Orthogonal Frequency Division Multiplexing (OFDM) symbols. In an embodiment, a plurality of signals occupying respective tones are received and processed to determine an order, based on a tone quality metric, for the plurality of signals. The plurality of signals are then dispatched to a pool of tree detectors in accordance with the order. In an embodiment, the order ensures that signals occupying higher quality tones, and requiring shorter detection times, are dispatched first to the pool of tree detectors. In another embodiment, a maximum runtime of busy tree detectors of the pool is updated based signal on actual detection times to exploit the time slack of early terminating detectors.

Abstract: Systems and methods are provided for encrypting a data transmission from a base station at the physical layer, such that the data transmission can only be decoded successfully by an intended UE. In an embodiment, a desired signal component, including a data signal for an intended UE, is combined with an interference component to generate a signal for transmission. The interference component is designed such that it falls in a null space of the channel from the base station to the intended UE and is therefore not received by the intended UE. In contrast, for an unintended UE, the interference component is designed to interfere with the desired signal component at the unintended UE, preventing the unintended UE from successfully decoding the data transmission.

Abstract: Where receiver performance at a User Equipment (UE) is similar using a coarse precoder codebook as using a fine resolution precoder codebook, the signaling of a two-component precoder codebook is modified such that a precoder codeword is signaled to the UE in only a portion of the physical resources allocated for precoder codeword signaling to the UE. The remaining portion of the allocated physical resources is used to signal control information to improve the UE's performance.

Abstract: The present disclosure is directed to a system and method for transitioning small cell base stations out of a discontinuous transmission (DTX) mode. The system and method comprise monitoring at the small cell base stations uplink transmissions from user terminals (UTs) to a macrocell base station while the small cell base stations are in the DTX mode. The small cell base stations can use the monitored uplink transmissions to, for example, measure received power levels from the UTs and/or measure uplink path losses between the small cell base stations and the UTs. The small cell base stations can report these measured values back to the macrocell base station through a backhaul network. Based on these measurements, the macrocell base station can determine which small cell base stations can support which UTs without transitioning the small cell base stations out of the DTX mode.

Abstract: Systems and methods for channel assignment configuration in a multiple access point (AP) environment are provided. The multiple APs can be homogeneous or heterogeneous and can implement one or more radio access technologies (RATs), including Massive Multiple Input Multiple Output (M-MIMO) RATs. A channel assignment configuration for a user equipment (UE) can identify one or more communication channels to be established to serve the UE by one or more of the APs.

Abstract: Systems and methods for enabling a wireless backhaul network between access points (APs) in a wireless network are provided. In an embodiment, the wireless backhaul network is enabled using a Massive Multiple Input Multiple Output (MIMO) radio access technology (RAT). In another embodiment, the wireless backhaul network is established using the same RAT as used by the APs to serve user devices, and can utilize the same time and frequency resources used for user communication.

Abstract: Embodiments recognize that in MIMO and M-MIMO systems, physical antennas tend to be closely spaced to each other (e.g., a grid). As a result, a spatial correlation typically exists between physical antennas as well as between transmissions from logical antenna ports. Embodiments exploit this characteristic to reduce the amount of pilot signaling needed to enable downlink channel estimation. Specifically, embodiments limit pilot signaling to only a subset of supported logical antenna ports and rely on spatial correlation information to interpolate channels from logic antenna ports for which no pilot signaling is used.

Abstract: Antenna systems and methods for Massive Multi-Input-Multi-Output (MIMO) (M-MIMO) communication are provided. Antennas systems include a M-MIMO transmitter architecture with a hybrid matrix structure. The hybrid matrix structure protects against transmit path component failures and ensures that a spatial rate of the MIMO transmitter is not degraded by the failures. Antenna systems and methods also include antenna selection schemes for selecting a subset of antennas from a plurality of antennas to transmit to a receiver.

Abstract: Embodiments provide systems and methods for enabling a first transceiver to learn beamforming weights (e.g., Eigen beamforming weights) to a second transceiver, without any pilot signaling or explicit beamforming weight signaling from the second transceiver. In another embodiment, beamforming weight vectors to enable a multi-symbol spatial rate can be learned by the first transceiver.

Abstract: A wireless communication device is disclosed that includes an automatic gain controller capable of accurately adjusting gain of a received signal. The received signal includes a plurality of symbols, including pilot symbols that each includes at least one pilot tone, and data symbols that do not include any pilot tones. A power of a pilot symbol is determined, and a power of a data symbol is determined. The determined data symbol power is then scaled by a scaling factor (that depends on various system parameters) and is subtracted from the determined pilot symbol power to provide an estimate of a power of the pilot tones within the signal. From the estimated pilot tone power, the automatic gain controller can accurately determine a preferred gain for amplifying future frames of the received signal.

Abstract: Methods and apparatus of allocating antennas for cyclic delay diversity (CDD) transmission are disclosed. One method includes estimating a transmission channel of a transceiver having a plurality of antennas. A subset of a plurality of transceiver antennas is selected based on the estimated transmission channel. A single transceiver antenna of the subset is identified based on a channel quality of a transmission path of the single transceiver antenna. Cyclic delay diversity (CDD) signals are transmitted from the subset of the plurality of antennas, wherein a minimally delayed CDD signal is transmitted from the identified single transceiver antenna of the subset of the plurality of transceiver antennas.

Abstract: A wireless communication device is disclosed that includes an automatic gain controller capable of accurately adjusting gain of a received signal. The received signal includes a plurality of symbols, including pilot symbols that each includes at least one pilot tone, and data symbols that do not include any pilot tones. A power of a pilot symbol is determined, and a power of a data symbol is determined. The determined data symbol power is then scaled by a scaling factor (that depends on various system parameters) and is subtracted from the determined pilot symbol power to provide an estimate of a power of the pilot tones within the signal. From the estimated pilot tone power, the automatic gain controller can accurately determine a preferred gain for amplifying future frames of the received signal.

Abstract: Methods and apparatus of allocating antennas for cyclic delay diversity (CDD) transmission are disclosed. One method includes estimating a transmission channel of a transceiver having a plurality of antennas. A subset of a plurality of transceiver antennas is selected based on the estimated transmission channel. A single transceiver antenna of the subset is identified based on a channel quality of a transmission path of the single transceiver antenna. Cyclic delay diversity (CDD) signals are transmitted from the subset of the plurality of antennas, wherein a minimally delayed CDD signal is transmitted from the identified single transceiver antenna of the subset of the plurality of transceiver antennas.