The methods and apparatus disclosed herein processes reference signals in an antenna diversity system, e.g., where both the transmitting and receiving devices use multiple antennas. The solution presented herein process reference signals at the transmitting device in such a way to enable the receiving device to efficiently and accurately estimate the covariance matrix associated with data transmitted using transmitter diversity. This is achieved by processing the reference signals used for the covariance estimation and the data signals in the same way, e.g., by precoding data and reference signal portions of one or more signals using the same coding scheme.

A transmitting device is disclosed. The transmitting device includes a controller that groups a plurality of transmitters into a plurality of groups including three or more groups and a plurality of code units that generate different output streams based on a data stream with respect to the plurality of groups. The controller delivers the output streams to the plurality of groups.

Methods and systems that can enable antenna selection (AS) and data bits in transmitted spatially modulated (SM) streams to be detected at a receiver using different detection methods. In example embodiments, encoding for an AS stream is done separately at a transmitter than encoding for data streams, enabling a receiver to use one type of detection for AS bits and a reduced complexity type of MIMO detection for the data bits.

Certain aspects of the present disclosure generally relate to wireless communications, and more specifically to increased diversity for devices with limited communications resources. An example method generally includes transmitting data as a bundled transmission to a device with limited communications resources, the bundled transmission comprising multiple bursts wherein each burst spans a plurality of transmission time intervals (TTIs) and the same data is transmitted in each burst, and taking action to increase diversity (e.g., at least one of spatial diversity, time diversity, frequency diversity, etc.) for the bundled transmission.

User equipment (UE) can include processing circuitry configured to decode radio resource control (RRC) signaling from a base station, the RRC signaling indicating a transmission coding scheme for a physical uplink shared channel (PUSCH) transmission. PUSCH-to-phase tracking reference signal (PT-RS) energy per resource element (EPRE) ratio is determined using the RRC signaling. A PT-RS power boosting factor is determined based on the transmission coding scheme and the PUSCH-to-PT-RS EPRE ratio. The PT-RS is encoded for transmission using a plurality of PT-RS symbols, the transmission using increased transmission power corresponding to the PT-RS power boosting factor. The RRC signaling further includes a flag enabling the PT-RS transmission. The PUSCH-to-PT-RS EPRE ratio is 00 or 01, and the transmission coding scheme is a codebook-based uplink transmission or non-codebook-based uplink transmission.

Methods and apparatuses are provided for receiving control information by a terminal. A control channel message is received on a control channel. Control information comprising a transmission rank and precoding matrix information is extracted from the control channel message if a common pilot is used for data demodulation. The control information comprising the transmission rank and information about a dedicated pilot is extracted from the control channel message if the dedicated pilot is used for the data demodulation.

A first wireless device determines a function of a Wake-Up (WU) Packet, selects a length of the WU Packet from a predetermined set of lengths corresponding to the function, and generates the WU packet having the selected length. The WU packet includes a Legacy preamble having a first bandwidth and a WU payload having a second bandwidth less than and included within the first bandwidth. The WU payload including an indication of the function and a control indication usable to select the length from the predetermined set of lengths corresponding to the function. The first wireless device transmits the WU packet by transmitting the Legacy preamble on the first bandwidth and then transmitting the WU payload on the second bandwidth. A second wireless device receives the WU payload and determines a length of the WU packet using the indication of the function and the control information.

The present invention relates to a method for transmitting, by a base station, a downlink signal using a plurality of transmission antennas comprises the steps of: applying a precoding matrix indicated by the PMI, received from a terminal, in a codebook to a plurality of layers, and transmitting the precoded signal to the terminal through a plurality of transmission antennas. Among precoding matrices included in the codebook, a precoding matrix for even number transmission layers can be a 22 matrix containing four matrices (W1s), the matrix (W1) having rows of a number of transmission antennas and columns of half the number of transmission layers, the first and second columns of the first row in the 22 matrix being multiplied by 1, the first column of the second row being multiplied by coefficient a of a phase, and the first column of the second row being multiplied by a.

Two-way (full-duplex) wireless communications. Various embodiments measure interference channels and provide for interference cancellation in both analog and digital domains to mitigate self-interference. The system supports multiple clients wherein new clients can join the network asynchronously, and also supports Multiple-Input Multiple-Output (MIMO) antennas.

Systems and methods are provided for introducing time diversity in a transmitter. The systems and methods may include receiving, at the transmitter, a request from a receiver to retransmit data. The systems and methods may further include receiving an input of data corresponding to the data requested for retransmission at a first transmitter block. The systems and methods may further include operating on the signals using the first transmitter block in at least one of a first mode and a second mode, such that an output of signals from the first transmitter block is dependent on a time-varying function and corresponds to the data requested by the receiver for retransmission.