Indication of an amount of processing performed in detection and removal of ingress noise may be provided. A frequency domain representation of a narrowband region of a digital input signal may be received. The received frequency domain representation of the narrowband region may be compared with a predetermined threshold. Results from the comparison of the received frequency domain representation of the narrowband region with the predetermined threshold may be aggregated. Based on the aggregated results, an indication of an amount of processing performed by an ingress excizer in removing the ingress noise may be provided.

A communication system including a transmitter and a receiver is disclosed. The transmitter transmits frames, at least two consecutive frames containing different training sequences. The receiver receives data communicated from the transmitter over a channel. The receiver combines and jointly processes the at least two consecutive frames transmitted by the transmitter to estimate a channel state of the channel.

A transceiver is disclosed which includes a transmitter and a receiver. The transmitter provides an impairment measurement signal, which is substantially similar to a transmitted communication signal except for a possible difference in phase and/or a magnitude, to the receiver. An envelope detector within the receiver provides an envelope of the impairment measurement signal to the transmitter. The transmitter determines sets of one or more filtering coefficients using the envelope of the impairment measurement signal and adjusts phases or magnitudes and/or phases of a sequences of bits used to generate the transmitted communication signal in accordance with the sets of one or more filtering coefficients to compensate for the unwanted distortion and/or the unwanted interference present within the transmitted communication signal.

A signal compensation method and device, where the method includes receiving a signal sequence suffering from intersymbol interference (ISI), setting a first filtering coefficient to perform filter compensation on the received signal sequence to obtain a first compensation signal sequence, setting a balance filtering coefficient to perform filter compensation on the first compensation signal sequence to obtain a balance compensation result, where the balance filtering coefficient is obtained by adjusting, according to a first compensation error, a balance filtering coefficient set last time, performing sequence estimation on the balance compensation result and outputting the balance compensation result, where the first compensation error adjusts the balance filtering coefficient set to perform filter compensation on the first compensation signal sequence in an iterative manner, thereby effectively compensating for the signal sequence suffering from the ISI, and improving performance of an optical fiber communications system.

A reverberator for reverberating an audio signal includes a feedback delay loop processor for delaying at least two frequency subband signals representing the audio signal by different loop delays to obtain reverberated frequency subband signals.

A method for estimating performance of a serial communication channel using processing circuits. The channel is configured to transmit a binary input stream from a transmitting end to an output stream at a receiving end. The method includes modeling by the processing circuits the channel at the receiving end as a first finite impulse response (FIR) system. The modeling includes estimating a cursor pulse response of the first FIR system by analyzing the output stream received at the receiving end, and estimating one or more pre-cursor or post-cursor pulse responses of the first FIR system from the received output stream using the estimated cursor pulse response. The method further includes determining by the processing circuits a performance metric by using the estimated one or more pre-cursor or post-cursor pulse responses.

A multi-tap Differential Feedforward Equalizer (DFFE) configuration with both precursor and postcursor taps is provided. The DFFE has reduced noise and/or crosstalk characteristics when compared to a Feedforward Equalizer (FFE) since DFFE uses decision outputs of slicers as inputs to a finite impulse response (FIR) unlike FFE which uses actual analog signal inputs. The digital outputs of the tentative decision slicers are multiplied with tap coefficients to reduce noise. Further, since digital outputs are used as the multiplier inputs, the multipliers effectively work as adders which are less complex to implement. The decisions at the outputs of the tentative decision slicers are tentative and are used in a FIR filter to equalize the signal; the equalized signal may be provided as input to the next stage slicers. The bit-error-rate (BER) of the final stage decisions are lower or better than the BER of the previous stage tentative decisions.

An adaptive equalizer and automatic gain controller is disclosed. The adaptive equalizer and automatic gain controller includes a programmable continuous time linear equalizer (CTLE). The CTLE includes a control port to receive a control signal to adjust a frequency response of the CTLE. The adaptive equalizer and automatic gain controller also includes a power comparator coupled with an output of the CTLE and a controller coupled with the power comparator and the control port and configured to generate the control signal for the CTLE based on the output of the power comparator. The power comparator is configured to compare power of a low frequency part and a high frequency part of an output signal of the CTLE.

A 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 circuitconfigured 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.

A reception device includes an equalization processing unit including a linear filter unit and a nonlinear filter unit and performing equalization process on a reception signal; a linear propagation channel estimation unit making propagation channel estimation using a known signal included in a reception signal to calculate a filter coefficient of the linear filter unit; and a synchronization processing unit performing synchronization process of correcting frequency deviation based on a signal output by the equalization processing unit, and when a predetermined condition is satisfied after executing first equalization process of outputting a reception signal filtered by the linear filter unit to the synchronization processing unit, the equalization processing unit starts second equalization process that is an adaptive equalization process of outputting a result of addition of a reception signal filtered by the linear filter unit and a reception signal filtered by the nonlinear filter unit to the synchronization processing unit.