Abstract: Embodiments of apparatus and method for calibration of a transceiver (including a transmitter and a receiver) are disclosed. In an example, a method for transmitter quadrature (or IQ) mismatch and receiver quadrature (or IQ) mismatch calibration can include controlling the transmitter to send a first transmit signal to the receiver with a delay between an output of the transmitter and an input of the receiver. The method can also include controlling the transmitter to send a second transmit signal to the receiver without the delay between the output of the transmitter and the input of the receiver. The method can further include obtaining compensation coefficients of the transceiver based on the sending of the first transmit signal and the sending of the second transmit signal.

Abstract: A PAM transceiver configured to process an electrical data signal having at least three states includes an electronic circuit comprising: a data interface configured to connect to a duplex communication channel; a first circuit section connected to the data interface; and a second circuit section connected to the data interface. The first circuit section includes an equalizer for compensating for distortions in the data signal and an interpreter downstream of the equalizer for recognizing symbols. The second circuit section includes a delay unit for time-shifting the data signal and an MMA processor for recognizing a signal phase of the data signal. The first circuit section and the second circuit sections are routed to the MMA processor. The second circuit section has a finite impulse response filter configured to monotonize an impulse response of the communication channel.

Abstract: A phase interpolation circuit with a high linearity includes a first parallel circuit constituted by M phase interpolation units, and a second parallel circuit constituted by N phase interpolation units. An input terminal of the first parallel circuit is connected to a first clock input terminal and grounded via a first capacitor. An input terminal of the second parallel circuit is connected to a second clock input terminal and grounded via a second capacitor. An output terminal of the first parallel circuit and an output terminal of the second parallel circuit are connected to a clock output terminal and grounded via a zeroth capacitor. A circuit parameter of each phase interpolation unit corresponds to a target output weight respectively. The target output weight of each phase interpolation unit is determined by iteration to minimize a phase difference between all output clock signals of the phase interpolation circuit.

Abstract: Certain aspects of the present disclosure provide techniques for wireless communications by a transmitter, comprising generating a waveform to be transmitted in one or more symbols, with a guard interval (GI) between adjacent symbols according to a GI configuration selected from a plurality of GI configurations, and transmitting the waveform with the GI between symbols.

Abstract: A method for tuning an envelope tracking (ET) system includes: determining a setting combination from a plurality of setting available to the ET system, wherein determining the setting combination from the plurality of setting available to the ET system includes: determining, by a processing module, a first setting in a plurality of first settings included in the plurality of settings, and configuring the ET system by the first setting; and after the ET system is configured by the first setting, determining, by the processing module, a second setting in a plurality of second settings included in the plurality of settings, and configuring the ET system by the second setting. In addition, the setting combination includes the first setting and the second setting.

Abstract: A matching circuit includes first and second input/output ports; first, second, and third coils; and a capacitor. The first coil is connected in series between the first and second input/output ports, and the second coil is connected in shunt between a ground and an input/output line between the first and second input/output ports. The first and second coils are magnetically coupled to each other, the third coil is magnetically coupled to at least one of the first and second coils, the capacitor is directly or indirectly connected to the third coil, and a closed circuit including the capacitor and the third coil is provided.

Abstract: A line card in a network box receives a SyncE clock signal and an input synchronization (SYNC) signal. A phase-lock loop (PLL) in the line card receives the SyncE clock signal as a reference clock signal and generates an output SyncE clock signal. The line card regenerates a SYSCLK signal using a digitally controlled oscillator that receives a timing signal from the SyncE PLL and receives a control signal from control logic on the line card. The frequency and phase information contained in the SYNC signal is utilized to control the DCO. The SYSCLK signal is divided to generate an output SYNC signal. The control logic uses the time difference between the input SYNC signal and a SYNC feedback signal to control the DCO to provide a zero delay SYNC output signal. The output SYNC signal and the SYSCLK signal control a time of day counter in the line card.

Abstract: Apparatus and methods for retraining digital pre-distortion are disclosed. In certain embodiments, a mobile device includes a transmit chain and a front end system. The transmit chain generates a transmit signal and converts the transmit signal to a radio frequency input signal, and includes a digital pre-distortion circuit that provides digital pre-distortion to the transmit signal. The front end system includes a power amplifier that amplifies the radio frequency input signal to generate a radio frequency output signal, and a power detector that generates a detection signal based on detecting an output power of the power amplifier. The detection signal controls initiation of a retraining sequence of the digital pre-distortion circuit.

Abstract: The present invention discloses a communication apparatus having feedback calibration mechanism. A signal transmission circuit generates a RF analog signal according to a digital signal. A signal amplifying circuit amplifies the RF analog signal to generate an amplified analog signal. A LC impedance matching circuit transmits the amplified analog signal to the antenna to perform transmission. A feedback calibration circuit includes a feedback inductive circuit and a calibration circuit. A feedback inductive circuit is inductively coupled to the LC impedance matching circuit to receive the amplified analog signal to generate a feedback signal. A calibration circuit determines a distorted amount of the feedback signal relative to the RF analog signal to modify an operation parameter of at least one of the signal transmission circuit and the signal amplifying circuit to decrease the distorted amount.

Abstract: A controller having a wireless transmission interface is provided. The controller includes an amplifier, an analog-to-digital converter, a digital filter, a processor, and a radio frequency signal transceiver. The amplifier is coupled to the wireless transmission interface, and generates an amplification signal according to an input signal. The analog-to-digital converter is coupled to the amplifier, and configured to convert the amplification signal into a digital format. The digital filter is coupled to the analog-to-digital converter, and configured to filter the amplification signal in the digital format to generate a filtered signal. The processor is coupled to the digital filter, and configured to perform a calculation on the filtered signal to generate a calculation result. The radio frequency signal transceiver is coupled to the processor, and obtains received information according to the calculation result and the filtered signal.

Abstract: This application provides a symbol processing method and related apparatus. The method includes: dividing a plurality of obtained complex-valued symbols into a plurality of sets, where each set corresponds to one transmit symbol, and the plurality of sets include a first set corresponding to a first transmit symbol; and mapping a first sequence and a second sequence to the first set, where an end position of the first sequence is a position of intercepting a cyclic prefix (CP) in the first transmit symbol, and an end position of the second sequence is an end position of the first transmit symbol. By mapping the sequences to the sets, an original cyclic prefix (CP) can be extended using a sequence with a flexible length, and flexible guard periods of different lengths can be configured for different users by adjusting the length of the sequences.

Abstract: Disclosed herein are devices, systems and methods between a between a plurality of collaborating Access Points (APs) and a receiving station (STA) operating in a wireless local area network (WLAN). The method include the steps of: transmitting, by each AP in the plurality of collaborating APs, a data frame to the receiving STA, each data frame has a preamble portion, the preamble portion including a signal (SIG) field, and the SIG field has a subfield including information representative of a total number of spatial streams transmitted by the plurality of collaborating Aps.

Abstract: An electronic device configured to apply, to a first power amplifier (PA) input, one or more updated memory digital pre-distorter (mDPD) coefficient values is provided. The electronic device includes a processor; and a memory including a non-transitory computer readable storage medium storing instructions that, when executed, cause the processor to preload, from values stored in the memory of the electronic device, one or more mDPD coefficient values; transmit a training signal sequence while using the preloaded one or more mDPD coefficient values; receive the training signal sequence; update the one or more mDPD coefficient values based on the transmitted training signal sequence, the received training signal sequence, and the preloaded one or more mDPD coefficient values; and apply the updated one or more mDPD coefficient values to distort the first PA input.

Abstract: A method for calibrating one or more compensation values utilized by a compensation device of a transmitter includes: obtaining a plurality of output signals which were sequentially generated by the transmitter by processing a pair of input signals according to multiple pairs of compensation values as a plurality of feedback signals, where each feedback signal corresponds to one of the multiple pairs of compensation values, determining a plurality of coefficients of a cost function according to the multiple pairs of compensation values and the feedback signals in an operation of calibration; and determining a pair of calibrated compensation values according to the coefficients and providing the pair of calibrated compensation values to the compensation device.

Abstract: There is provided a method of transmitting and receiving data across a network. A receiver device comprises a recovery module comprising a neural network trained to recover signals from clipped signals. The transmitter device may clip the original signal more aggressively due to the improved performance of the machine-learning based recovery module, thereby reducing the Peak to Average Power Ratio (PAPR) of the signal.

Abstract: A configuration for beam management procedure using OAM beams. The apparatus transmits, to a receiver, a positive phase order OAM transmission on at least one beam. The apparatus transmits, to the receiver, a negative phase order OAM transmission on the at least one beam. The apparatus receives, from the receiver, a report indicating a relative phase difference between the positive phase order OAM transmission and the negative phase order OAM transmission.

Abstract: Methods and apparatus for providing an adaptive beamforming antenna for OFDM-based communication systems. In one embodiment, a method includes forming a matrix (A) of cyclic prefix values and a matrix (B) of tail values from an orthogonal frequency division multiplexed (OFDM) symbol, and forming a summation matrix (S) and a difference matrix (D) from the matrix A and the matrix B. The method also includes multiplying a beamformer preset matrix (W) with the matrix S and the matrix D to determine a matrix (P) and a matrix (Q), and determining a beam identifier from the P and Q matrices.

Abstract: An example test system includes memory (e.g., one or more memory devices) storing (i) instructions that are executable, and (ii) a mapping function that relates first error vector magnitudes (EVMs) for first symbols to second EVMs for the first symbols, where the first EVMs are corrupted by radio frequency (RF) noise and the second EVMs are corrupted by both RF noise and symbol decoding errors. The test system also includes a decoder to receive a signal from a device under test, and to obtain a third EVM for a second symbol that is based on the signal, where the third EVM is corrupted by both RF noise and a symbol decoding error. One or more processing devices are configured to execute the instructions to adjust the third EVM using the mapping function to correct the symbol decoding error in the third EVM.

Abstract: A communication apparatus includes a receiver and a decoder. The receiver includes a plurality of antenna elements and, in operation, receives from a base station apparatus a modulated signal mapped to one of a plurality of subframes defined in a frame corresponding to a communicable range to which the communication apparatus belongs. The plurality of subframes are defined by time-division, frequency-division, or time-and-frequency division of the frame. A maximum number of modulated signals that can be simultaneously transmitted in a subframe from the base station apparatus varies depending on the communicable range. The decoder, in operation, decodes the received modulated signal.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may perform online spur detection and mitigation scheme. The UE may identify spurs during operation, in real time, and apply cancelation and noise equalization to address identified spurs. The UE may apply a high pass filter to reference signals. During a symbol, the UE may apply the high pass filter by estimating the channel on one or more neighbor tones (e.g., tones of higher frequency and tones of lower frequency that also carry reference symbols). Because the UE may assume that a channel will generally be smooth, and that noise may vary slowly or steadily across frequency resources, the UE may compare the channel noise of a particular tone to an average or normalized channel noise of the one or more neighbor tones.