An apparatus performs a discrete Fourier transform process on M×N received signal components included in a received signal, by a unit of N received signal components; and estimates an estimated signal containing M×N estimated signal components, which are estimated values of M×N transmission signal components, on the basis of the received signal on which the discrete Fourier transform process is performed. When the estimated signal xe is newly estimated, the apparatus performs an exclusion operation of excluding an estimated value xe.sup.(k) of the M transmission signal components that constitute a k-th transmission signal group from the estimated signal xe newly estimated, and updates the estimated value xe′ based on an intermediate signal xt.sup.(k) obtained by the exclusion operation and the received signal, thereby re-estimating the estimated signal xe.

Consistent with the present disclosure, an encoder circuit is provided at a transmit side of an optical fiber link that maps an input sequence of bits of fixed length k a sequence of symbols of a codeword of length n, such that the symbols of the codeword define a predetermined transmission probability distribution. Preferably, each symbol of the codeword is generated during a corresponding clock cycle, such that after n clock cycles, a complete codeword corresponding to the input bit sequence is output. On a receive end of the link, a decoder is provided that outputs the k-bit sequence every n clock cycles. Accordingly, buffers need not be provided at the output of the encoder and the input of the decoder, such that processing of the input sequence, codewords, and output sequence may be achieved efficiently without large buffers and complicated circuitry. Moreover, the input sequence, with any binary alphabet may be matched to a desired output distribution with any arbitrary alphabet. Accordingly, probabilistic constellation shaping may be achieved over constellations of arbitrary size. In addition, relatively long codewords, may be encoded and decoded with the apparatus and method disclosed herein. Accordingly, for a fixed SNR a higher SE (more bits per symbol) can be achieved. Alternatively, for a fixed SE, a lower SNR may be sufficient. Moreover, the resulting SE may be finely tailored to a particular optical link SNR to provide data transmission rates that are higher than the low order modulation formats that would otherwise be employed for optical signals carried by such links.

A wireless communication method for transmitting wireless signals from a transmitter includes receiving information bits for transmission, segmenting the information bits into a stream of segments, applying a corresponding forward error correction (FEC) code and an interleaver to each of the stream of segments and combining outputs of the interleaving to generate a stream of symbols, processing the stream of symbols to generate a waveform, and transmitting the waveform over a communication medium.

An electronic system includes a feedforward equalizer, a feedback equalizer, an RFI canceler, and a control circuit. The feedforward equalizer and the feedback equalizer are configured to adjust the channel response of a transmission channel in the electronic system. The RFI canceler is configured to cancel the RFI presence in the electronic system. When the RFI canceler is off, the controller is configured to turn on the RFI canceler according to a signal error value before RFI cancelation, an error term of the electronic system, or an SNR of the electronic system.

Consistent with the present disclosure, an encoder circuit is provided at a transmit side of an optical fiber link that maps an input sequence of bits of fixed length k a sequence of symbols of a codeword of length n, such that the symbols of the codeword define a predetermined transmission probability distribution. Preferably, each symbol of the codeword is generated during a corresponding clock cycle, such that after n clock cycles, a complete codeword corresponding to the input bit sequence is output. On a receive end of the link, a decoder is provided that outputs the k-bit sequence every n clock cycles. Accordingly, buffers need not be provided at the output of the encoder and the input of the decoder, such that processing of the input sequence, codewords, and output sequence may be achieved efficiently without large buffers and complicated circuitry. Moreover, the input sequence, with any binary alphabet may be matched to a desired output distribution with any arbitrary alphabet. Accordingly, probabilistic constellation shaping may be achieved over constellations of arbitrary size. In addition, relatively long codewords, may be encoded and decoded with the apparatus and method disclosed herein. Accordingly, for a fixed SNR a higher SE (more bits per symbol) can be achieved. Alternatively, for a fixed SE, a lower SNR may be sufficient. Moreover, the resulting SE may be finely tailored to a particular optical link SNR to provide data transmission rates that are higher than the low order modulation formats that would otherwise be employed for optical signals carried by such links.

An improved receiver design implements a method for modeling users in SIC turbo loop multiuser detection architectures that reduces the number of implementation cycles, and thereby reduces the computational overhead associated with computing the inverse of the received signal covariance matrix, by efficiently reusing components of a QR decomposition. By reusing some of the computational results from the previous turbo loop's equalizer calculation, the disclosed receiver significantly reduces the computational burden of updating the linear equalizer on each turbo loop. Depending on the embodiment, this reduction can be accomplished in at least two different ways, depending on the dimensionality and other aspects of the implementation.

An integrated circuit for a receiving link device includes a processing device to detect, using an equalizer of the receiving link device, that a receiver (RX) pre-cursor value is outside of a threshold value based on a target RX tap value. The processing device further generates, based on the detecting, a plurality of tap messages having a plurality of up or down commands to one of decrease or increase a corresponding transmitter (TX) pre-cursor value of a transmitting link device. The processing device further causes the plurality of tap messages to be provided to a local transmitter to be transmitted to the transmitting link device. The plurality of tap messages is to cause the transmitting link device to adjust the corresponding TX pre-cursor value.

A system for optimum phase searching in an Ethernet physical layer includes a time recovering circuit and an equalizer. The time recovering circuit includes a loop filter and a time error detector, and the equalizer includes a feed forward equalizer, a slicer and a feed backward equalizer. An optimum phase searching method includes obtaining optimum phases when mean squared errors calculated by the slicer are less than a first threshold, absolute values of mean values of outputs calculated by a time error detector are less than a second threshold, and the outputs are monotonic.

A wireless communication method for transmitting wireless signals from a transmitter includes receiving information bits for transmission, segmenting the information bits into a stream of segments, applying a corresponding forward error correction (FEC) code and an interleaver to each of the stream of segments and combining outputs of the interleaving to generate a stream of symbols, processing the stream of symbols to generate a waveform, and transmitting the waveform over a communication medium.

Consistent with the present disclosure, an encoder circuit is provided at a transmit side of an optical fiber link that maps an input sequence of bits of fixed length k a sequence of symbols of a codeword of length n, such that the symbols of the codeword define a predetermined transmission probability distribution. Preferably, each symbol of the codeword is generated during a corresponding clock cycle, such that after n clock cycles, a complete codeword corresponding to the input bit sequence is output. On a receive end of the link, a decoder is provided that outputs the k-bit sequence every n clock cycles. Accordingly, buffers need not be provided at the output of the encoder and the input of the decoder, such that processing of the input sequence, codewords, and output sequence may be achieved efficiently without large buffers and complicated circuitry. Moreover, the input sequence, with any binary alphabet may be matched to a desired output distribution with any arbitrary alphabet. Accordingly, probabilistic constellation shaping may be achieved over constellations of arbitrary size. In addition, relatively long codewords, may be encoded and decoded with the apparatus and method disclosed herein. Accordingly, for a fixed SNR a higher SE (more bits per symbol) can be achieved. Alternatively, for a fixed SE, a lower SNR may be sufficient. Moreover, the resulting SE may be finely tailored to a particular optical link SNR to provide data transmission rates that are higher than the low order modulation formats that would otherwise be employed for optical signals carried by such links.