The present invention discloses a DAC method having signal calibration mechanism is provided. Operation states of current sources are controlled to generate an output analog signal by a DAC circuit according to a codeword of an input digital signal. An echo signal is generated by an echo transmission circuit according to the output analog signal. The codeword is mapped to generate an offset signal by a calibration circuit according to a codeword offset mapping table. The offset signal is processed to generate an echo-canceling signal by an echo-canceling circuit. By a calibration parameter calculation circuit, offset amounts are generated according to a difference between the echo signal and the echo-canceling signal, the offset amounts are grouped to perform statistic operation according to the operation states and current offset values are calculated according to calculation among groups and converted to codeword offset values to update the codeword offset mapping table.

A power line communication apparatus includes a first power line communication device disposed at a signal transmit end, a second power line communication device disposed at a signal receive end, a power line, a first magnetic ring disposed at the signal transmit end, and a second magnetic ring disposed at the signal receive end. The second power line communication device receives the modulated signal from the power line. The power line includes a wire for transmitting electric energy and a shield layer that wraps the wire for electromagnetic shielding. The wire and the shield layer separately extend from the signal transmit end to the signal receive end. The first magnetic ring and the second magnetic ring are separately coupled to the shield layer, to suppress inductance attenuation of the magnetic ring and improve reliability of the transmitted modulated signal.

A transceiver includes a first digital-to-analog converter (DAC), a second DAC, and a timing control module. In a calibration mode, the first DAC transmits a transmitting signal; the second DAC transmits an echo cancellation signal; and the timing control module, according to an echo signal of the transmitting signal and the echo cancellation signal, obtains a timing offset therebetween, and generates a first timing control signal and a second timing control signal to the first DAC and the second. DAC according to the timing offset, respectively. The first DAC adjusts a transmission delay of transmitting the transmitting signal according to the first timing control signal, and/or the second DAC modifies a transmission delay of transmitting the echo cancellation signal according to the second timing control signal.

A method of double talk detection includes using up-sampling. Audio signals received from the far end are up-sampled prior to output by the loudspeaker at the near end. The microphone at the near end captures audio at the up-sampled rate, and the audio output by the loudspeaker is detectable due to having no energy in the up-sampled frequency bands. The double talk detector uses this information to generate a signal for suppressing the echo of the far end audio from the captured audio signal that is transmitted to the far end.

A digital-to-analog converter circuit generates an analog transmitted signal according to a digital transmitted signal. A first echo canceller circuit generates a first echo cancelling signal according to the digital transmitted signal. A processor circuit generates an analog processed signal according to the analog transmitted signal, the first echo cancelling signal, and a received signal. An analog-to-digital converter circuit generates a digital value according to the analog processed signal and two slicer levels of a plurality of slicer levels. A storage circuit stores a look-up table. The look-up table records an offset value corresponding to the digital value. The storage circuit further outputs a first output signal according to the digital value and the offset value. The offset value is updated according to an error value associated with the first output signal.

A digital-to-analog converter circuit generates an analog transmitted signal according to a digital transmitted signal. A first echo canceller circuit generates a first echo cancelling signal according to the digital transmitted signal. A processor circuit generates an analog processed signal according to the analog transmitted signal, the first echo cancelling signal, and a received signal. An analog-to-digital converter circuit generates a digital value according to the analog processed signal and two slicer levels of a plurality of slicer levels. A storage circuit stores a look-up table. The look-up table records an offset value corresponding to the digital value. The storage circuit further outputs a first output signal according to the digital value and the offset value. The offset value is updated according to an error value associated with the first output signal.

A system, in an active reflector device, adjusts a first amplification gain of each of a plurality of radio frequency (RF) signals received at a receiver front-end from a first equipment via a first radio path of an NLOS radio path. A first phase shift is performed on each of the plurality of RF signals with the adjusted first amplification gain. A combination of the plurality of first phase-shifted RF signals is split at a transmitter front-end. A second phase shift on each of the split first plurality of first phase-shifted RF signals is performed. The plurality of RF signals as a directed beam is transmitted to a second equipment via a second radio path of the NLOS radio path.

An echo cancellation method includes receiving an echo reference signal, receiving a microphone signal, decomposing, with a first filter bank, the echo reference signal into a series of subband echo reference signals, decomposing, with a second filter bank, the microphone signal into a series of subband microphone signals, estimating a group delay between the echo reference signal and the microphone signal using the series of subband echo reference signals and the series of subband microphone signals, estimating, using adaptive filters, acoustic echoes in the echo reference signal based at least in part on the group delay, subtracting the acoustic echoes from the series of subband microphone signals to obtain a series of acoustic echo removed subband signals, combining the series of acoustic echo removed subband signals into a single time domain echo removed signal, and sending the single time domain echo removed signal to a host operating system.

An electronic device, an echo signal cancelling method thereof and a non-transitory computer readable recording medium is provided. The electronic device according to an exemplary embodiment includes a speaker configured to output a sound corresponding to a reference signal, a microphone configured to generate a microphone signal by obtaining a received sound, and a filter configured to cancel an echo signal of the reference signal from the microphone signal. In addition, the filter includes a first filter configured to estimate an echo signal of the reference signal and cancel the estimated echo signal from the microphone signal, and a second filter configured to generate an adaptive gain to cancel a residual echo from the microphone signal in which the estimated echo signal is canceled, and generate an output signal by using the generated adaptive gain and the microphone signal in which the estimated echo signal is canceled.

The systems and methods discussed herein utilized a wireless or wired transceiver having a transmitter and a receiver. The transceiver is configured to reduce distortion contributions associated with echo cancelling. The transmitter provides a replica signal and a transmit signal. The replica signal and the transmit signal can be provided using a common switch.