A driver circuit of a PAM-N transmitting device transmits a PAM-N signal via a communication channel, wherein N is greater than 2, and the PAM-N signal has N signal levels corresponding to N symbols. A PAM-N receiving device receives the PAM-N signal. The PAM-N receiving device generates distortion information indicative of a level of distortion corresponding to inequalities in voltage differences between the N signal levels. The PAM-N receiving device transmits to the PAM-N transmitting device the distortion information indicative of the level of the distortion. The PAM-N transmitting device receives the distortion information. The PAM-N transmitting device adjusts one or more drive strength parameters of the driver circuit of the PAM-N transmitting device based on the distortion information.

A communication device, including a receiver configured to receive a signal from a transmitter, the signal including a plurality of data symbols; and at least one processor configured to: obtain a channel estimate and an estimated carrier frequency offset based on a result of an interference detection indicating whether interference is detected in the plurality of data symbols, obtain a data symbol of the plurality of data symbols, obtain a compensated data symbol corresponding to the data symbol based on the estimated carrier frequency offset, obtain an equalized compensated data symbol by performing channel equalization on the compensated data symbol based on the channel estimate, and demodulate and decode the equalized compensated data symbol to obtain decoded data.

In accordance with an embodiment of the present invention, a method for receiving a signal, comprising the estimation step for estimating time and frequency shifts that are embedded in the received signal, to cancel-out shifts, wherein the method refers to the non-commutative shift parameter space of co-dimension 2.

A digital transmission system includes a transmitter configured to transmit an orthogonal frequency division multiplexing (OFDM) signal along a signal path, a receiver for receiving the OFDM signal from the transmitter and extracting OFDM symbols from the received OFDM signal, and a diagnostic unit configured to (i) demodulate the received OFDM signal to create an ideal signal, (ii) compare the received OFDM signal with the ideal signal to calculate an error signal, (iii) cross-correlate the error signal with the ideal signal, and (iv) determine a level nonlinear distortion from one of the transmitter and the signal path based on the correlation of the error signal with the ideal signal.

A method and apparatus are provided. The method includes receiving, by at least one antenna of a receiver, at least one signal from a transceiver, detecting at least one data symbol within the at least one signal, determining a probability associated with the at least one detected data symbol, determining channel state information (CSI) of at least one channel between the transceiver and the at least one antenna of the receiver, and estimating a common phase error (CPE) of the at least one signal based on the probabilities associated with the at least one detected data symbol and the CSI of the at least one channel.

The present disclosure provides a method in a receiver for frequency offset estimation. The method includes: for each of two or more pairs of symbols in a set of symbols from a transmitter: calculating a phase difference between a first symbol and a second symbol in the pair; and removing from the calculated phase difference a phase difference component due to a difference between information carried in the first symbol and information carried in the second symbol, to obtain a residual phase difference component. The method further includes: estimating a frequency offset between the receiver and the transmitter as a function of the respective residual phase difference components obtained for the two or more pairs.

A digital transmission system includes a transmitter configured to transmit an orthogonal frequency division multiplexing (OFDM) signal along a signal path, a receiver for receiving the OFDM signal from the transmitter and extracting OFDM symbols from the received OFDM signal, and a diagnostic unit configured to (i) demodulate the received OFDM signal to create an ideal signal, (ii) compare the received OFDM signal with the ideal signal to calculate an error signal, (iii) cross-correlate the error signal with the ideal signal, and (iv) determine a level nonlinear distortion from one of the transmitter and the signal path based on the correlation of the error signal with the ideal signal.

Methods and systems are provided for using error related feedback during signal processing. During handling of an input signal, each of a plurality of sub-carriers in the input signal is processed, and error-related information for each one of the plurality of sub-carriers is determined based on the processing. Aggregate error-related information is generated based on error-related information of each of one of the plurality of sub-carriers, and subsequent processing of at least one of the sub-carriers is adjusted based on the aggregate error-related information. The error-related information may comprise phase error-related information. Adjustments to subsequent processing of one or more of the sub-carriers may be determined based on processing-related information corresponding to different stages during processing of each of the plurality of sub-carriers.

A method and apparatus are provided. The method includes receiving, by at least one antenna of a receiver, at least one signal from a transceiver, detecting at least one data symbol within the at least one signal, determining a probability associated with the at least one detected data symbol, determining channel state information (CSI) of at least one channel between the transceiver and the at least one antenna of the receiver, and estimating a common phase error (CPE) of the at least one signal based on the probabilities associated with the at least one detected data symbol and the CSI of the at least one channel.

A robust frequency drift tracking receiver. The received signal is translated to an intermediate frequency in the RF stage by a quadrature demodulator, and is then brought into the base band by a digital mixer made by a CORDIC. A base band processing stage allows for a synchronization of the receiver relative to the data frame, to estimate data and to output a counter-reaction signal to the CORDIC, obtained by integration of successive frequency corrections, with a predetermined step.