A PAM4 receiver including an adaptive continuous-time linear equalizer and a method for training the same are disclosed. The PAM4 receiver and the method for training the same of the present invention employs a training pattern including a first training data pattern and second training data pattern to adaptively tune the PAM4 receiver to achieve accurate data reception and long-distance, high-speed communication.

This application provides a training sequence transmission method and apparatus. The method includes: A first AP broadcasts a trigger frame, where the trigger frame indicates a time sequence of separately sending channel sounding frames by N STAs, and N is an integer greater than 1. The first AP receives the channel sounding frames sequentially sent by the N STAs, where one channel sounding frame includes one or more training sequences. In this solution, only one trigger frame needs to be sent, so that the N STAs can be triggered to separately report channel sounding frames to M+1 APs. However, in the conventional technology, each AP needs to send one channel training request to each STA, that is, N×(M+1) channel training requests are sent in total, to trigger each STA to report a training sequence. Therefore, this solution can significantly reduce signaling overheads.

Systems and methods for improving the efficiency of a rotational dynamic element matching (DEM) for Delta Sigma converters. In some implementations, the systems and methods are provided a for reducing intersymbol interference (ISI) of a Delta Sigma converter. A delta sigma converter architecture can include multiple I-DACs, and the output from each I-DAC can vary from the other I-DACs. Techniques are disclosed for decreasing mismatch among multiple I-DACs while improving efficiency of rotational dynamic element matching.

A wireless communication device is described. The wireless communication device includes a receiver. The receiver is configured to determine a time-domain sample of a single carrier based on a received signal. The receiver is also configured to determine an estimated value based on the time-domain sample. The receiver is further configured to perform slicing based on the estimated value to produce a sliced value. The receiver is additionally configured to adapt a frequency-domain coefficient based on the estimated value and the sliced value. The receiver is also configured to perform channel equalization based on the frequency-domain coefficient.

receiver may include a first filter configured to generate a first estimation of a symbol of a received signal and a second filter configured to generate a second estimation of the symbol of the received signal. The receiver may also include a decoder configured to decode the symbol using one of the first estimation and the second estimation and a decision circuit configured to select one of the first estimation and the second estimation to provide to the decoder for decoding of the symbol based on a comparison of the first estimation to an estimation threshold.

Apparatuses, systems, and techniques to perform signal processing operations in a fifth generation (“5G”) radio signal. In at least one embodiment, one or more processors equalize, in parallel, one or more 5G radio signals.

An apparatus performs a discrete Fourier transform process on M×N received signal components included in a received signal, by a unit of N received signal components; and estimates an estimated signal containing M×N estimated signal components, which are estimated values of M×N transmission signal components, on the basis of the received signal on which the discrete Fourier transform process is performed. When the estimated signal xe is newly estimated, the apparatus performs an exclusion operation of excluding an estimated value xe.sup.(k) of the M transmission signal components that constitute a k-th transmission signal group from the estimated signal xe newly estimated, and updates the estimated value xe′ based on an intermediate signal xt.sup.(k) obtained by the exclusion operation and the received signal, thereby re-estimating the estimated signal xe.

An apparatus may comprise a skew detection circuit to sample a common mode voltage of a differential signal, wherein the sampled common mode voltage is indicative of an amount of skew between a first signal of the differential signal and a second signal of the differential signal; and a skew compensation circuit to adjust a delay of the first signal or the second signal based on the sampled common mode voltage to reduce the amount of skew.

Systems, methods, and apparatuses for wireless communication are described. Input data for in-phase branch/quadrature branch (I/Q) imbalance or mismatch may be compensated for or non-linear power amplifier noise may be used to generate compensated input data. In some examples, a transmitter may be configured to transmit communications signaling via a first antenna, the transmitter including a filter configured for digital mismatch correction; a receiver may be configured to receive communications signaling via a second antenna; and a switch may be configured to selectively activate a first switch path to couple the transmitter and the first antenna and a second switch path to couple the receiver and the transmitter to provide communications signaling received via the transmitter as feedback for the filter through the receiver.

Joint estimation of the framer index and the frequency offset in a optical communication system are described among various other features. A transmitter can transmit data frames using pilot and framer symbols. A receiver can estimate the framer index and frequency offset using the pilot and framer symbols, and identify the beginning of a header portion of a data frame. The estimation can be performed to compensate for delays such as half-symbol delays and differential group delays. By identifying the beginning of the header portion of a data frame while compensating for certain delays, the receiver can synchronize, with less error, the data transmitted by the transmitter and the data it received.