A communication system includes a first physical-layer (PHY) transceiver and a second PHY transceiver. The first PHY transceiver includes (i) a first transmitter and (ii) a first receiver including a first equalizer. The second PHY transceiver includes (i) a second transmitter and (ii) a second receiver including a second equalizer. The first PHY transceiver and the second PHY transceiver are configured to communicate with one another over a full-duplex link, including training the first equalizer on a second training signal transmitted from the second PHY transceiver, and concurrently training the second equalizer on a first training signal transmitted from the first PHY transceiver.

An echo canceller system includes a data transmitter circuit and an echo canceller circuit. The data transmitter circuit is configured to receive a transmitted signal. The echo canceller circuit includes a first filter. The first filter is configured to generate a first filtered signal according to the transmitted signal and a filter coefficient vector. The filter coefficient vector is updated according to a high-frequency leakage process. The echo canceller circuit is further configured to generate an echo cancelling signal according to the first filtered signal. The data transmitter circuit is further configured to generate an output signal according to a received signal and the echo cancelling signal.

Disclosed are systems, methods, and non-transitory computer-readable media for a segmented ECF that includes multiple filter components to replicate an echo pulse response. The different filter components are used to replicate different portions of the echo pulse response. Each filter components can include filter coefficients of different sizes based on the portions of the echo pulse response that is replicated by the filter component. For example, a filter component that replicates a portion of the echo pulse response that includes a large reflection can include large filter coefficients suitable to replicate the larger reflection. In contrast, a filter component that replicates a portion of the echo pulse response that includes smaller reflections can include smaller filter coefficients that are suitable to replicate the smaller reflection. The output of each of the filter components is combined to replicate the full echo pulse response.

A channel detection method for an echo canceller of a communication device is provided. The method includes the following steps. A first detection signal is transmitted to an end of a channel coupled to the communication device. A plurality of taps corresponding to a reflected signal of the first detection signal are received by an echo canceller at the end of the channel. The taps corresponding to the reflected signal are compared with a reference value corresponding to each of the taps so as to determine whether each of the taps is larger than or equal to the corresponding reference value. When the tap is determined to be larger than or equal to the reference value corresponding to the tap, the tap and a position of the tap are recorded.

A device capable of autonomous motion includes a residual echo suppressor for suppressing echoes caused by an output reference signal. When the device outputs audio while moving with a velocity, it may receive echoes that are Doppler-shifted due to the motion. The residual echo suppressor generates estimated residual error data based on phase-shifted reference data to account for and suppress the Doppler-shifted echoes.

Techniques for enhancing an acoustic echo canceller based on visual cues are described herein. The techniques include changing adaptation of a filter of the acoustic echo canceller, calibrating the filter, or reducing background noise from an audio signal processed by the acoustic echo canceller. The changing, calibrating, and reducing are responsive to visual cues that describe acoustic characteristics of a location of a device that includes the acoustic echo canceller. Such visual cues may indicate that no human being is present at the location, that some subject(s) are engaged in speaking or sound generating activities, or that motion associated with an echo path change has occurred at the location.

An echo cancellation device and an echo cancellation method thereof applied in a communication device are provided. The echo cancellation device includes an echo canceller and a combine circuit. The echo canceller obtains a plurality of delayed signals from a local signal of the communication device, and the delayed signals are divided into a plurality of delayed signal groups. The echo canceller selectively ignores at least one of the delayed signal groups, and the echo canceller generates an echo cancellation signal with the others of the delayed signal groups. The combine circuit is coupled to an interface circuit of the communication device to receive a received signal. The combine circuit cancels an echo component of the received signal with the echo cancellation signal to generate a cancelled signal.

An echo canceller system includes a data transmitter circuit and an echo canceller circuit. The data transmitter circuit is configured to receive a transmitted signal. The echo canceller circuit includes a first filter. The first filter is configured to generate a first filtered signal according to the transmitted signal and a filter coefficient vector. The filter coefficient vector is updated according to a high-frequency leakage process. The echo canceller circuit is further configured to generate an echo cancelling signal according to the first filtered signal. The data transmitter circuit is further configured to generate an output signal according to a received signal and the echo cancelling signal.

An operation method is implemented by a receiver device. The operation method includes following steps: detecting a signal on a transmission line; performing a channel estimation to acquire a length of the transmission line; comparing the length with at least one length threshold value to generate a comparison result; and adjusting a depth of a FIFO process according to the comparison result.

An operation method is implemented by a receiver device. The operation method includes following steps: detecting a signal on a transmission line; performing a channel estimation to acquire a length of the transmission line; comparing the length with at least one length threshold value to generate a comparison result; and adjusting a depth of a FIFO process according to the comparison result.