Aspects of this disclosure provide techniques for detecting and recovering from beam-failure events. In some embodiments, motion sensor information generated by motion sensors on a UE is used to detect, predict, and/or recover from a beam failure event that results, or would otherwise result, from movement of the UE. The motion sensor information may be used to adjust a current beam direction used by the UE to transmit or receive a signal, or to determine a recommendation for adjusting a current beam direction of the base station. The motion sensor information may be generated by any sensor that detects a movement of the UE, such as a gyroscope, an accelerometer, a magnetometer, a global positioning system (GPS) sensor, a global navigation satellite system (GNSS) sensor, or any other device that detects a change in position/orientation of the UE.

Spatial multiplexing and transmit diversity can improve the capacity of a wireless communication system. The system and method adapts communication schemes for communication systems with multiple antennas utilizing at least two transmission modes. The at least two transmission modes can, but are not necessarily, used for uplink communications. The two transmission modes may be chosen from the group consisting of a single antenna mode, a diversity mode a spatial multiplexed mode and a mixed diversity and spatial multiplexed mode. The at least two transmission modes may involve adaptation among multiple transmitters. At least one receiver may indicate a transmission mode to be used by a transmitter for a subsequent transmission. A transmitter may determine a transmission mode to be used for a subsequent transmission. The transmission mode can be based on channel sounding.

An antenna array comprises a plurality of antenna elements including a first antenna element having a longitudinal direction along a plane, a second antenna element having a longitudinal direction along the plane and located adjacent to the first antenna element, and a third antenna element having a longitudinal direction along the plane and located adjacent to the first antenna element. The first and second antenna elements are aligned in a row in a vertical direction along the plane. The first and third antenna elements are aligned in a row in a horizontal direction along the plane. A center of the second antenna element in the longitudinal direction thereof is placed on an extended line of the first antenna element drawn in the longitudinal direction. A center of the first antenna element in the longitudinal direction thereof is placed on an extended line of the third antenna element drawn in the longitudinal direction.

A communication device configured to operate in a Multiple-input Multiple-output (MIMO) operation mode and Single-input Single output (SISO) operation mode and operation mode switching method are described. The communication device can include a transceiver associated with a first antenna, and configured to wirelessly communicate via the first antenna using a first communication technology; a second antenna associated with a second communication technology different from the first communication technology; and a controller coupled to the transceiver. The controller can be configured to: determine communication information corresponding to the first and the second communication technologies; and control the communication device to switch an operation mode of the communication device between the MIMO operation mode and the SISO operation mode based on the determined communication information.

Methods and systems are provided for using decision feedback phase error correction during signal processing. When an input signal comprises a plurality of sub-carriers, each of the plurality of sub-carriers may be processed separately, for each one of the plurality sub-carriers error related information may be determined separately, based on the processing of that sub-carrier. Subsequent processing of at least one of the plurality of sub-carriers may then be adjusted based on determined error related information corresponding to one or more sub-carriers. In this regard, the subsequent processing of the at least one sub-carrier may be adjusted based on determined error related information for that sub-carrier, based on determined error related information for at least one other sub-carrier, or based on determined error related information corresponding to all of the sub-carriers. The error related information may comprise phase error related information.

Provided is a technique related to a terminal apparatus, a base station apparatus, a communication system, a communication method, and an integrated circuit that are capable of efficiently performing device-to-device communication. In a case where a terminal apparatus capable of direct communication between terminal apparatuses starts a timer corresponding to a group index that identifies short-range group communication, to which the terminal apparatus belongs, and the timer expires, switching is performed from a first radio resource allocation method, by which a radio resource to be used for the direct communication is requested to a base station apparatus, to a second radio resource allocation method by which the terminal apparatus selects a radio resource to be used for the direct communication.

Systems and method for adaptive constellation mapping determine transmission formats for simultaneous transmission from multiple transmitter chains. The adaptive constellation mapping can select a winning combination of mappings using distance metrics. The distance metrics can be calculated from estimated received signal constellations at a multi-layer receiver. The multi-layer receiver can separate the data received from each of the transmitter chains. Additional systems and method can determine a whether to use adaptive constellation mapping or an alternate transmission format. Further systems and methods can determine a transmit arrangement that include selection of which of multiple transmitters will be a part of an adaptive constellation mapping transmission, the number of layers that will be transmitted by each transmitter, the transmitter chains that will be used, and which of multiple antennas that will be used.

Systems and methods are disclosed that facilitate creating antenna ports to correspond to two or more groups of user equipment. The systems and methods can organize two or more groups of user equipment and signal to each of the two or more groups a respective antenna port. The systems and methods can further communicate mapping information, a reference signal, or delay related to a linear combination in order to identify antenna ports. Based on such communicated information, the reference signal can be decoded in order to identify each antenna port.

The embodiments herein relate to a method in a transmitter for transmitting a data burst to a receiver in a system supporting GSM and/or EGPRS. The transmitter is arranged to make its transmissions with or without beamforming. The transmitter comprises at least two Tx antennas. When the data burst is beamformed, the transmitter transmits the data burst to the receiver through at least one of the at least two Tx antennas. The data burst comprises a common training sequence. When the data burst is non-beamformed, the transmitter transmits the data burst to the receiver through each of the at least two Tx antennas. The data burst comprises a respective antenna specific training sequence.

Certain aspects of the present disclosure generally relate to passive positioning based on directional transmissions, such as directional beacons transmitted during a sector sweep procedure.