Abstract:
Systems and methods are provided for estimating non-linearity of a transmitter, a receiver or both based on measurements and/or feedback. The estimation of the non-linearity may be used at the transmitter, the receiver or both to tune one or more components to reduce non-linearity. In one aspect, a method for wireless communications comprises generating at least one training signal, and outputting the at least one training signal for transmission to a wireless node. The method also comprises receiving a feedback message from the wireless node, the feedback message providing feedback of the at least one training signal received at the wireless node. The method further comprises tuning at least one component based on the feedback message.
Abstract:
In certain aspects of the present disclosure, an apparatus for wireless communications is provided. The apparatus comprises a plurality of block circuits, wherein each one of the plurality of block circuits is configured to receive a respective plurality of signals from a respective subset of antenna elements of an antenna array. Each one of the plurality of block circuits comprises a respective plurality of phase shifters configured to shift phases of the respective plurality of signals to obtain a respective plurality of phase-shifted signals, and a respective combiner configured to combine the respective plurality of phase-shifted signals into a respective combined signal. The apparatus also comprises a plurality of time-delay elements configured to delay the combined signals to obtain a plurality of delayed combined signals, and a combiner configured to combine the plurality of delayed combined signals into a total combined signal.
Abstract:
Certain aspects of the present disclosure are directed to digital predistortion (DPD) for use with a multi-chain wireless transmitter. In various examples described herein, the multi-chain transmitter is configured to use a single common DPD device or module for all transmit chains and to adjust the bias voltages of the power amplifiers of the separate transmit chains to operate at substantially the same backoff so the distortion to the corresponding output signals is similar. Since the distortion of the output of the different chains is similar, a single common predistortion may be applied using the single DPD device to a signal to be transmitted. Techniques are also described for calibrating the predistortion coefficients of the DPD to optimize (or otherwise set) the amount of distortion reduction to be achieved. The predistortion coefficients for the single DPD may be set or calibrated based on a particular directionality needed for beamforming.
Abstract:
In certain aspects of the present disclosure, an apparatus for wireless communications comprises a processing system configured to generate a frame comprising first information indicating a plurality of channels to be used by the apparatus for a transmission and second information indicating a time duration of the transmission. The apparatus also comprises an interface configured to output the frame for wireless transmission on at least one of the plurality of channels. In certain aspects of the present disclosure, another apparatus receiving the frame may determine the plurality of channels based on the first information, compute a time duration based on the second information, and avoid transmitting on the plurality of channels for at least the computed time duration (e.g., to avoid collision).
Abstract:
A technique is disclosed for reducing interference in a communication system including a plurality of wireless devices. A first device transmits an RTS-TRN frame including a Request to Send (RTS) portion and a first beam training sequence to determine whether a communication medium is available to communicate with a second device. If the communication medium is available, the second device transmits a CTS-TRN frame including a Clear to Send (CTS) portion and a second beam training sequence. One or more neighboring devices that receive the RTS-TRN frame and/or the CTS-TRN frame configure their respective antennas to generate one or more nulls aimed at the first and second devices when transmitting signals, as long as the first and second devices are communicating based on a duration field in the RTS-TRN frame and/or CTS-TRN frame. This reduces interference at the first and/or second devices.
Abstract:
An apparatus for wireless communications is disclosed. The apparatus includes a processing system configured to generate a frame having a preamble, a header, and a data payload, wherein the preamble, the header, and the data payload are decodable by a first device when operating according to a first protocol, wherein the preamble and the header are decodable by a second device when operating according to a second protocol, the data payload not being decodable by the second device when operating according to the second protocol; and an interface configured to output the frame for transmission.
Abstract:
Certain aspects of the present disclosure provide an apparatus for wireless communications. The apparatus includes a processing system configured to generate a frame comprising a first channel estimation sequence for transmission via a first channel, a second channel estimation sequence for transmission via a second channel, and at least a first portion of a data payload for transmission via a third channel, wherein the first channel includes a first frequency band, wherein the second channel includes a second frequency band different from the first frequency band, and wherein the third channel includes a third frequency band that overlaps in frequency with the first and second frequency bands; and an interface configured to output the frame for transmission.
Abstract:
Certain aspects of the present disclosure provide an apparatus for wireless communications. The apparatus includes a processing system configured to generate a frame comprising a preamble, a first header, and a second header, wherein the preamble and the first header are configured to be decoded by a first device operating according to a first protocol, the second header not being configured to be decoded by the first device, and wherein the preamble, the first header, and the second header are configured to be decoded by a second device operating according to a second protocol; and an interface configured to output the frame for transmission.
Abstract:
Certain aspects of the present disclosure provide an apparatus for wireless communications. The apparatus includes a processing system configured to generate a frame comprising a first channel estimation sequence for transmission via a first channel, a second channel estimation sequence for transmission via a second channel, and at least a first portion of a data payload for transmission via a third channel, wherein the first channel includes a first frequency band, wherein the second channel includes a second frequency band different from the first frequency band, and wherein the third channel includes a third frequency band that overlaps in frequency with the first and second frequency bands; and an interface configured to output the frame for transmission.
Abstract:
Certain aspects of the present disclosure provide methods and apparatuses for generating a frame for wireless transmission, wherein the frame comprises a payload including a plurality of blocks, each block comprising a data portion and a plurality of pilots distributed in the data portion. The distributed pilots may be used by a receiver receiving the frame to perform phase tracking during the data portions of the blocks to reduce phase noise.