The present invention provides a multi-rate bidirectional transmission system. A sending device and a receiving device transmit data in a bidirectional way through a cable. The multi-rate bidirectional transmission system communicates with a reverse configuration packet by sending a forward configuration packet at a preset rate in a time-division manner, selects a serial rate jointly supported by the sending device and the receiving device, and selects a training sequence length. Then, the sending device and the receiving device perform equalization training at the selected serial rate with the selected training sequence length, thus avoiding searching the serial rate and presetting the training sequence length in the worst case, thus simplifying the design and improving the link training speed.

Enhanced phase-noise mitigation is possible at low-to-no cost. Communication at the high frequencies envisioned for late 5G and 6G will require much better phase-noise control than current frequency bands, because the tight margins will result in excessive phase faults and greatly reduced throughput. The disclosed examples show how to use two modulation schemes to provide the best phase margins at the final step. For example, the message can be initially modulated in classical amplitude-phase modulation as transmitted, but is received and processed using convenient QAM orthogonal components. Then the receiver can convert the results back to the amplitude-phase modulation scheme analytically, and can finally demodulate using calibrated amplitude and phase levels derived from a proximate demodulation reference. Since the amplitude-phase modulation scheme provides substantially larger phase margins than QAM with the same information content, substantially higher frequencies can be accessed while retaining high reliability.

An electronic control unit is mounted on a vehicle, and includes a reception unit that receives a data signal transmitted via a transmission path mounted on the vehicle; an environmental information acquisition unit that acquires environmental information of the vehicle; and a determination unit that determines the state of the transmission path, in which the reception unit includes an equalizer that compensates for the data signal, the equalizer calculates a compensation parameter for compensating for the data signal, and the determination unit determines the state of the transmission path based on the compensation parameter and the environmental information.

Optical transmitters and receivers for improving synchronization of data transmitted over an optical network are described. The receiver can perform non-linear filtering as part of framer index estimation operations to improve the synchronization. The receiver can determine estimated positions of framer indices in data frames received from the transmitter. Next, using a non-linear filter, the receiver can remove estimated positions that are likely erroneous or are greater than a threshold away from the median or mode estimated framer index position. By removing the likely erroneous estimated positions, the receiver can then determine the estimated position of a framer index position for multiple frames with greater confidence.

Methods and apparatus for successive interference cancellation (SIC). In an embodiment, a method includes receiving symbols from a plurality of user equipment (UE), identify a target UE and non-target UEs, decoding code blocks from the symbols received from the non-target UEs to generate decoded bits for each code block. The method also includes performing a CRC check on each code block to generate a tag (0) when the CRC check passes and a tag (1) when the CRC check fails, and re-encoding the decoded bits to generate re-encoded code blocks having the associated tags attached. The method also includes reconstructing symbols from the re-encoded code blocks where symbols reconstructed from re-encoded code blocks having tag (0) are reconstructed with data and symbols reconstructed from re-encoded code blocks having tag (1) are reconstructed as zero value symbols, and utilizing the reconstructed symbols to cancel interference on symbols from the target UE.

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 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 l-DACs. Techniques include decreasing mismatch among multiple l-DACs while improving efficiency of rotational dynamic element matching.

Described herein are systems and methods that perform coarse chromatic dispersion (CD) compensation by applying precomputed coarse front-end equalizer (FEE) tap weights to a receiver based on an assumed propagation distance. After a waiting period, the FEE tap weights are applied, and it is determined whether the FEE tap weights cause a decision-directed tracking of channel rotations to satisfy a stability metric. In response to the stability metric not being satisfied, the assumed propagation distance is adjusted and used to obtain updated FEE tap weights. Conversely, if the stability metric is satisfied, a fine CD compensation is performed that comprises maintaining the updated FEE tap weights; performing an iterative least-mean-squared (LMS) error adaption to adjust Back-End Equalizer (BEE) tap weights and obtain updated BEE tap weights; and using the updated BEE tap weights to adjust the FEE tap weights to, ultimately, have the BEE output an equalized data bit stream.

A receiver included in a memory device includes a flag generator circuit, an equalizer circuit and an equalization controller circuit. The flag generator circuit is configured to, during a normal operation mode, generates a flag signal without an external command. The equalizer circuit is configured to, during the normal operation mode, receive an input data signal through a channel, generate an equalized signal by equalizing the input data signal based on an equalization coefficient, and generate a data sample signal including a plurality of data bits based on the equalized signal. The equalization controller circuit is configured to, during the normal operation mode, determine an amount of change in the equalization coefficient based on the flag signal, the equalized signal and the data sample signal, and perform a training operation in which the equalization coefficient is updated in real time based on the amount of change in the equalization coefficient.

A method for equalizing a wireless communication channel includes transmitting a data signal over a primary channel. During transmission of the data signal, a corresponding data signal is sent over a secondary channel. The information received from the secondary channel is compared to the information received from the primary channel and differences between the information received from each of the channels are observed. These differences are used as inputs to an equalizer algorithm that may be used to reduce distortion of the data signal sent over the primary channel.

In some embodiments, a method receives a first signal that is sent in a first direction in a network. Communications in the network are full duplex communications in a same frequency band. The first signal is amplified in the first direction. The method trains a first echo canceller to cancel a first echo signal from the first signal where the first echo signal is received in a second direction. After training the first echo canceller, the trained first echo canceller is enabled. The method receives a second signal in the second direction that is sent in the second direction in the network. The second signal is amplified in the second direction. The method trains a second echo canceller to cancel a second echo signal received in the first direction from the second signal where the first echo canceller cancels the first echo signal that is received in the second direction.