An apparatus for communication in a wireless communication network comprises a coder that encodes a set of data symbols to produce a set of coded symbols; a modulator that modulates the coded symbols onto a set of subcarrier frequencies to generate a time-domain signal comprising a sum of a set of modulated pulse waveforms; and a transmitter configured for transmitting the time-domain signal in the wireless communication network. The coder employs a matrix of spreading codes, wherein each column of the matrix multiplies a different one of the data symbols, which causes the modulator to produce a corresponding one of the set of modulated pulse waveforms. Each column of the matrix of spreading codes comprises a set of linearly increasing phases, which provides a time offset to the corresponding modulated pulse waveforms.

In a mmW network, a UE and a base station may establish a link using a RACH procedure. Because mmW and other band communications may rely on accurate beamforming to overcome link attention, the UE may need to provide beam information feedback to the base station. In particular, the UE may receive a beam-formed message from the base station during the RACH procedure. The UE may determine beam information based on the received beam-formed message during the RACH procedure. The UE may transmit a message to the base station during the RACH procedure, and the message may include the determined beam information.

Methods, systems, and devices for wireless communication are described. A wireless device (e.g., an access point or a station) capable of supporting multiple chain configuration modes may monitor traffic on a wireless channel. The wireless device may, based on the monitoring, determine a series of values for a metric that is indicative of communication conditions. The metric may be a packet rate, channel congestion, or signal strength. The wireless device may dynamically select one of the supported chain configuration modes in which to operate based on the series of values for the metric. In some cases, the wireless device may compute a value for the metric based on the series of values and compare the value of the metric to a predetermined threshold. In such cases, selection of the chain configuration mode may be based on the results of the comparison. In some examples, one or metrics may be used.

Aspects of the present disclosure include methods and devices for wireless communication including an apparatus, e.g., a UE. The apparatus may be configured to receive one or more reference signals from each transmit beam of a set of transmit beams of a first base station through each receive beam of a set of receive beams of the UE. The apparatus may be further configured to determine a set of transmit-beam receive-beam pairs based on the received reference signals. The apparatus may be further configured to determine a subset of the transmit-beam receive-beam pairs of the set of transmit-beam receive-beam pairs that are mutually non-interfering with each other. The apparatus may be further configured to transmit, to a second base station, a report indicating information associated with the subset of the transmit-beam receive-beam pairs.

Methods and apparatus for orthogonal stream spatial multiplexing. In one embodiment, a method includes splitting and modulating a data stream into n MIMO RF spatial streams and coupling them to corresponding switchable polarization antenna elements controlled via orthogonal binary codes for transmission. Each transmitted stream manifests as time-varying-polarization-orthogonal to the other n−1 spatial streams. The method includes reception of the streams at their destination using corresponding antenna elements controlled by the same set of orthogonal codes. Thus, each of the n transmitted spatial streams is polarization-match-filtered, unambiguously separated and individually recovered from all the others upon reception for subsequent demodulation and MIMO spatial recombination into the original data stream. Thus, n MIMO spatial streams emanating from a common source and featuring equal amplitude and bandwidth but bearing distinct data and exhibiting mutually orthogonal time varying polarization will propagate mutually interference-free on the same frequency channel to a single destination.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, via multiple UE receive beams, one or more reference signals transmitted over a wideband, the wideband including one or more subbands. The UE may transmit a report based at least in part on one or more measurements of the one or more subbands. Numerous other aspects are described.

A transmission method simultaneously transmitting a first modulated signal and a second modulated signal at a common frequency performs precoding on both signals using a fixed precoding matrix and regularly changes the phase of at least one of the signals, thereby improving received data signal quality for a reception device.

Apparatuses, methods, and systems are disclosed for preparing channel state information (“CSI”). One apparatus includes a processor and a transceiver configured to communicate with a base unit over a radio access network using at least one transmission layer and determining a total number of non-zero coefficients over a set of layers. The processor encodes the total number of non-zero coefficients by selecting a codeword from a plurality of candidate codewords in which the selected single codeword identifies the total number of non-zero coefficients to the base unit. The processor prepares CSI, where the CSI comprises the selected single codeword encoding the total number of non-zero coefficients and the transceiver transmits the CSI to the base unit.

An apparatus that communicates in a mobile radio communications network, comprises signal-processing circuitry for provisioning a consecutive series of Orthogonal Frequency Division Multiplexing (OFDM) subcarriers for uplink or downlink communications; provisioning a plurality of different selectable subcarrier spacings for the consecutive series of OFDM subcarriers; performing discrete Fourier transform (DFT) coding on a plurality of data symbols to produce DFT coded symbols; and performing an inverse-DFT on the coded symbols to produce a single-carrier frequency division multiple access signal that comprises a sum of the consecutive series of OFDM subcarriers. The single-carrier frequency division multiple access signal is provided with a particular one of a set of different symbol periods by selecting one of the plurality of different selectable subcarrier spacings.

An example method for estimating the angle-of-arrival (AoA) and other parameters of radio frequency (RF) signals that are received by an antenna array comprises: receiving a plurality of radio frequency (RF) signal power measurements by a plurality of antenna elements at a plurality of RF channels; computing, by applying a machine learning model to the plurality of RF signal power measurements, an estimated RF signal parameter value; and outputting the RF signal parameter value.