Abstract: A signal processing method including the steps of: using a FFT window to process a last symbol of a first sub-frame of a frame to generate a frequency-domain signal, wherein the FFT window has a first start point; performing an IFFT operation on the frequency-domain signal to generate a channel impulse response; performing a channel estimation on the channel impulse response to generate a channel profile; referring to the channel profile of the last symbol of the first sub-frame, an attribute of a start symbol of a second sub-frame and the first FFT window start point to determine a second FFT window start point; using the FFT window having the second start point to process the start symbol of the second sub-frame to generate another frequency-domain signal.

Abstract: A method for hybrid digital-analog beamforming a communication system. The method includes obtaining a plurality of transmit phase shifted signals by obtaining a hybrid precoding matrix FH. The hybrid precoding matrix FH is obtained based on a plurality of dominant right eigenvectors of a first effective channel matrix associated with a set of wireless channels. The hybrid precoding matrix FH includes a product of a digital precoding matrix F B ? B ( 1 ) and an analog precoding matrix FRF. Each entry of the analog precoding matrix FRF includes one of zero or a respective complex value with unit magnitude. Obtaining the plurality of transmit phase shifted signals further includes obtaining a digital precoding matrix F B ? B ( 2 ) based on the hybrid precoding matrix FH. Each wireless channel in the set of wireless channels is associated with a base station and a respective user equipment (UE) in a set of UEs.

Abstract: A symbol boundary detection method includes: calculating desired signal power according to a receiving signal by a receiver device; calculating interference power according to the receiving signal by the receiver device; calculating a signal-to-interference power ratio according to the desired signal power and the interference power by the receiver device; finding a best signal-to-interference power ratio to determine a reference symbol boundary time by the receiver device; and processing the receiving signal according to the reference symbol boundary time by the receiver device for a subsequent demodulation process performed by a demodulator circuit.

Abstract: A data modulator for a transmitter includes a multiplexer configured to receive, at a first rate, a first data stream including a plurality of first symbols and a second data stream including a plurality of second symbols. The multiplexer is configured to selectively output, based on a first clock signal, the plurality of first symbols and the plurality of second symbols to form a third data stream that achieves a second rate greater than the first rate for transmission of the third data stream by the transmitter.

Abstract: A beam forming device, a calibration method and a calibration system using the same are provided. The beam forming device includes a processor, a memory unit, a baseband circuit, and a plurality of antenna modules. The antenna modules each includes multiple antenna elements, and multiple phase shifters and multiple of amplifiers respectively corresponding to the antenna elements. The memory unit stores a reference codebook, a plurality of calibration codebooks and instructing data, each of the plurality of calibration codebooks includes a plurality of records of calibration control data divided by a plurality of target patterns, and a plurality of predetermined phase differences that are different from each other respectively existed between the plurality of calibration codebooks and the reference codebook. The instruction data is used for instructing the beamforming device to use one of the reference codebook and the plurality of calibration codebooks in transmitting and receiving signals.

Abstract: There is provided a method for exchanging spatial information of signals received from a User Equipment (UE) between a radio unit and a baseband unit. The method comprises: determining a channel estimate based on signals received from a User Equipment (UE); selecting a spatial transformation to be applied to the received signals, based on the channel estimate; and sending a set of signals transformed by the selected transformation to a baseband unit. A radio unit for implementing this method is also provided.

Abstract: Antenna systems are provided. In one example, an antenna system includes a first antenna array having a plurality of first antenna elements. The first antenna elements are operable to communicate one or more signals via a communication protocol tin a multiple input multiple output (MIMO) mode. The antenna system includes a second antenna array having a plurality of second antenna elements. The antenna system includes a control circuit configured to control operation of one or more of the second antenna elements of the second antenna array in a first mode or a second mode. In the first mode, one or more of the second antenna elements are configured to provide a secondary function to support communication of the first antenna elements via the communication protocol. In a second mode. One or more of the second antenna elements are configured to support beam forming or beam steering of the first antenna elements.

Abstract: A method and a device in a communication node used for wireless communications is disclosed in the present disclosure. The communication node first receives first information and second information; and transmits a first radio signal in a first time window; and then transmits a second radio signal; the first information is used to determine a target time window, the second radio signal occupies a second time window in time domain, and the second information is used to determine at least one of whether the second time window belongs to the target time window or a relative position relationship between the second time window and the target time window; an end of the first time window is earlier than a start of the target time window. The present disclosure helps improve the utilization ratio of resources in Grant-Free transmission.

Abstract: In one embodiment an apparatus includes: a mixer to downconvert a radio frequency (RF) spectrum including at least a first RF signal of a first channel of interest and a second RF signal of a second channel of interest to at least a first second frequency signal and a second second frequency signal; a first digitizer to digitize the first second frequency signal to a first digitized signal, the first digitizer configured to operate as a low-pass analog-to-digital converter (ADC); a second digitizer to digitize the second second frequency signal to a second digitized signal, the second digitizer configured to operate as a band-pass ADC; and a digital processor to digitally process the first digitized signal and the second digitized signal.

Abstract: A communication method and a communications node includes sending, by a sending node, a first frame to a receiving node on a first channel, and sending at least one second frame to the receiving node on a second channel, where a frequency of the first channel is less than a frequency of the second channel, where each second frame corresponds to a sending direction, and a length of each second frame is less than a preset frame length.

Abstract: The application provides a short training sequence design method and apparatus. The method includes: determining a short training sequence, where the short training sequence may be obtained based on an existing sequence, and the short training sequence with comparatively good performance may be obtained through simulation calculation, for example, by adjusting a parameter; and sending a short training field on a target channel, where the short training field is obtained by performing inverse fast Fourier transformation IFFT on the short training sequence, and a bandwidth of the target channel is greater than 160 MHz.

Abstract: Methods and apparatuses for low-latency beam selection. A method for operating user equipment (UE) includes receiving configuration information on a set of uplink (UL) beams and at least one associated sounding reference signal (SRS) resource. Each of the UL beams is associated with one RS resource. The method further includes detecting that an event occurs; calculating an UL beam reporting associated with at least one of the UL beams; initiating or receiving a request for an SRS transmission; and transmitting the UL beam reporting after the event occurs.

Abstract: Systems and methods for differential data transmission using an unterminated transmission line comprise a plurality of switches configured to control a differential voltage output on a pair of output lines, wherein the plurality of switches have a first state in which a high voltage is output on a first of the pair of output lines and a low voltage is output on a second of the pair of output lines, and wherein the plurality of switches have a second state in which the low voltage is output on the first of the pair of output lines and the high voltage is output on the second of the pair of output lines. A transition switch with an output impedance equal to that of the output lines will discharge the lines during a state transition so as to reduce to power consumption associated with changing states of the transmission line.

Abstract: For example, an EDMG STA may generate an LDPC coded bit stream for a user based on data bits for the user in an EDMG PPDU, the LDPC coded bit stream for the user including a concatenation of a plurality of LDPC codewords, a count of the plurality of LDPC codewords is based at least on a codeword length for the user and on a code rate for the user; generate encoded and padded bits for the user by concatenating the LDPC coded bit stream with a plurality of coded pad zero bits, a count of the coded pad zero bits is based at least on a count of one or more spatial streams for the user and on the count of the plurality of LDPC codewords for the user; and distribute the encoded and padded bits for the user to the one or more spatial streams for the user.

Abstract: A clock generation circuit for generating a plurality of output clocks includes: a differential circuit for receiving a single input clock signal and outputting two differential clock signals, and a DC signal; a first polyphase filter for generating four clock signals from the differential clock signals which are a quadrature phase apart from each other; a plurality of setting buffers for setting a same DC point for the four clock signals and generating four resultant clock signals; coupled polyphase filters for generating four more clock signals which are a quadrature apart from each other, and outputting the resultant eight clock signals; a phase mixer, for generating eight output clock signals 45 degrees apart from each other; and a plurality of restoration buffers for setting a DC point for each of the eight clock signals and generating eight output clock signals all riding on a same DC point.

Abstract: Methods, systems, and devices related to applying a spreading code to reference signals are described. In one exemplary aspect, a method for wireless communication includes receiving a message indicating a set of control options available to the mobile device for data transmissions. The method includes selecting a spreading code sequence from a number of spreading code sequences, wherein the spreading code sequence corresponds to a control option in the set of control options, wherein the number of spreading code sequences is greater than a length of each of the spreading code sequence, and wherein the spreading code sequences are generated using a method when the length of each of the spreading code sequences is greater than or equal to a value. The method also includes generating a plurality of reference signal symbols using the spreading code sequence, and transmitting the plurality of reference signal symbols.

Abstract: One example discloses an OFDM wireless communications device, including: a memory configured to support processing of OFDM tones; a controller, coupled to the memory, and configured to set the wireless communication device to a first mode and a second mode; wherein the first mode is configured to transmit or receive a first wireless communication signal having a first set of OFDM tones contained within an OFDM channel bandwidth; wherein the second mode is configured to transmit or receive a second wireless communication signal having a second set of OFDM tones contained within the OFDM channel bandwidth; and wherein the memory used for processing the first set of OFDM tones is same as the memory used for processing the second set of OFDM tones.

Abstract: Apparatus and methods for envelope alignment calibration in radio frequency (RF) systems are provided. In certain embodiments, calibration is performed by providing an envelope signal with a peak along an envelope path, and by providing an RF signal with a first peak and a second peak to a power amplifier along an RF signal path. Additionally, an output of the power amplifier is observed to generate an observation signal using an observation receiver. The observation signal includes a first peak and a second peak corresponding to the first peak and the second peak of the RF signal, and a delay between the envelope signal and the RF signal is controlled based on relative size of the peaks of the observation signal to one another.

Abstract: A MIMO transceiver may include a communication chain configured to generate a signal at a first frequency and that includes a pre-distorter configured to accept pre-distortion parameters to pre-distort signals and a PA to amplify the signals. The MIMO transceiver may include a DPD chain configured to receive the signal at the first frequency and that includes a data converter to sample the signal using a sampling rate based on a baseband frequency and to generate a sample signal based on the sampling of the signal. The MIMO transceiver may include a buffer configured to buffer the sample signal. The MIMO transceiver may include a DPD circuit configured to calibrate the pre-distortion parameters based on the buffered sample signal. The MIMO transceiver may include a CTS circuit to transmit a CTS-to-Self signal within an operational environment to reserve a duration of time for the MIMO transceiver to perform DPD calibration.

Abstract: Examples described herein include methods, devices, and systems which may compensate input data for non-linear power amplifier noise to generate compensated input data. In compensating the noise, during an uplink transmission time interval (TTI), a switch path is activated to provide amplified input data to a receiver stage including a coefficient calculator. The coefficient calculator may calculate an error representative of the noise based partly on the input signal to be transmitted and a feedback signal to generate coefficient data associated with the power amplifier noise. The feedback signal is provided, after processing through the receiver, to a coefficient calculator. During an uplink TTI, the amplified input data may also be transmitted as the RF wireless transmission via an RF antenna. During a downlink TTI, the switch path may be deactivated and the receiver stage may receive an additional RF wireless transmission to be processed in the receiver stage.