Abstract: A method for calibrating mismatches of an in-phase signal path and a quadrature signal path of a transmitter, including: additionally configuration at least one mixer calibration coefficient at a transmitting part of the transmitter; obtaining at least one mixer testing signal from the transmitting part via loopback for spectrum analysis to derive at least one mixer spectrum analysis result; adjusting the mixer calibration coefficient of the transmitting part according to the mixer spectrum analysis result; and additionally utilizing an in-phase signal path finite impulse response filter and a quadrature signal path finite impulse response filter to calibrate mismatches between a low pass filter of the in-phase signal path of the transmitting part of the transmitter and a low pass filter of the quadrature signal path of the transmitting part of the transmitter. A similar mismatch calibration operation may be applied to a receiver.

Abstract: Logic may comprise a single phase tracking implementation for all bandwidths of operation and the logic may adaptively change pre-defined and stored track parameters if the receiving packet is 1 MHz bandwidth. Logic may detect a packet and long training fields before performing a 1 MHz classification. Logic may auto-detect 1 MHz bandwidth transmissions by a property of the long training field sequences. Logic may auto-detect 1 MHz bandwidth transmissions by detecting a Binary Phase Shift Keying (BPSK) modulated first signal field symbol rather than the Quadrature Binary Phase Shift Keying (QBPSK) associated with the 2 MHz or greater bandwidth transmissions. Logic may perform an algorithm to determine an estimated phase correction value for a given orthogonal frequency division multiplexing symbol and several embodiments integrate this value with an intercept multiplier that may be 0.2 for 1 MHz transmissions and, e.g., 0.5 for 2 MHz or greater bandwidth communication.

Abstract: An Automatic Identification System—AIS—receiver comprising at least one processing section (PS1, PS2) for synchronizing, demodulating and detecting AIS messages contained in a received signal, said processing steps being carried out separately for a plurality of frequency sub-bands (SB1, SB2, SB3) spanning an AIS channel (CH1, CH2); the receiver being characterized in that: said sub-bands overlap with each others; and said or each processing section is adapted for synchronizing, demodulating and detecting said AIS messages within each sub-band on the basis of timing error and carrier frequency estimations obtained from filtered replicas of said received signal, propagating along respective auxiliary signal paths.

Abstract: A receiving apparatus receives an FSK signal, converts the FSK signal into a phasor including amplitude and phase, estimates and compensates for a CFO (carrier frequency offset) from the converted phasor, and recovers a data bit from the converted phasor.

Abstract: A receiver includes a positive pulse determination circuit and a negative pulse determination circuit. The positive pulse determination circuit outputs a first L-level between when a pulse signal having a negative amplitude is detected and when neither a pulse signal having a positive amplitude nor a pulse signal having a negative amplitude is detected; otherwise a first H-level if a pulse signal having a positive amplitude is detected during another period. The negative pulse determination circuit outputs a second L-level between when a pulse signal having a positive amplitude is detected and when neither a pulse signal having a positive amplitude nor a pulse signal having a negative amplitude is detected; otherwise a second H-level is output if a pulse signal having a negative amplitude is detected during the other period.

Abstract: Provided is a transmitter for transmitting signals by means of the STBC method or the DSTBC method, wherein communication is carried out effectively. The transmitter for transmitting signals by means of the STBC method or the DSTBC method has the following configuration. A frame in which synchronization words are arranged at specified positions is used. An encoding means in the transmitter encodes the entire frame to be transmitted including the synchronization words, by means of the STBC method or the DSTBC method. It is also possible to implement a communication system and a communication method for communicating signals by means of the STBC method or the DSTBC method.

Abstract: A technique for decoding a signal in a communication network is provided. A method implementation of the technique comprises the steps of receiving a signal; identifying a position in the signal; initializing a Viterbi state metric; and decoding the encoded signal by means of a wrap-around Viterbi algorithm. The received signal comprises information, wherein the signal is encoded by a tail-biting convolutional code. The identified position relates to a known portion of the information. The initialized Viterbi state metric is consistent with the known portion of the information. The decoding uses the initial Viterbi state metric, wherein the decoding starts at a decoding step following the identified position.

Abstract: Systems and techniques relating to wireless communications are described. A described technique includes aligning a received data sequence with a transmitted data sequence to produce an aligned data sequence, the received data sequence being based on an output of a power amplifier having one or more nonlinear characteristics that is responsive to the transmitted data sequence; dividing the aligned data sequence into N segments; obtaining first nonlinear parameters for the power amplifier based at least on first segments of the N segments; obtaining a second nonlinear parameter(s) corresponding to a second segment(s) of the N segments based on an extrapolation of the first nonlinear parameters, the second segment(s) having a lower transmitted data sequence value(s) than the first segments; and performing digital predistortion on a transmit data sequence based on the nonlinear predistortion parameters to compensate for the one or more nonlinear characteristics of the power amplifier.

Abstract: A compensator generating a compensation signal to compensate for nonlinear echo in an output of a current source. The nonlinear echo is a result of transitioning the current source between an ON state and an OFF state. The compensator includes driving, weighting, function, and compensating circuits. The driving circuit receives a first signal that is based on the output of the current source. The weighting circuit is configured to generate a second signal based on weighted versions of the first signal. The function circuit, based on the second signal, (i) updates each of multiple functions, and (ii) selects a first function. The driving circuit generates a driving signal based on the first function selected by the function circuit. The compensating circuit generates the compensation signal based on the driving signal to compensate for the nonlinear echo provided by the output of the current source.

Abstract: An optical communication system, a transmitter, a receiver, and methods of operating the same are provided. In particular, a transmitter is disclosed as being configured to encode optical signals in accordance with a multi-level coding scheme. The receiver is configured to provide receive and decode to the optical signals received from the transmitter. One or both of the receiver and transmitter are configured to compensate for non-idealities or non-linearities introduced into the communication system by optical components of the system.

Abstract: Wireless communication wherein channel estimation accuracy is improved while keeping the position of each bit in a frame, even when a modulation system having a large modulation multiple value is used for a data symbol. An encoding operation encodes and outputs transmitting data (bit string) and a bit converting operation converts at least one bit of a plurality of bits constituting a data symbol to be used for channel estimation, among the encoded bit strings, into or ‘0’ or ‘0’. A modulating operation modulates the bit string inputted from the bit converting operation by using a single modulation mapper and a plurality of data symbols are generated.

Abstract: An orthotope sphere decoding method of a multiple antenna system is disclosed. The method includes performing tree search using a depth-first method by performing an OC-test on the nodes on which the tree search of orthotope sphere decoding will be performed and performing an SC-test on nodes passing the OC-test; and selecting a transmission symbol having a smallest PED value as a final signal as a result of the search.

Abstract: The present invention discloses a method and system for adaptively identifying signal bandwidth. The method includes: performing digitizing intermediate frequency processing to the received signal and outputting in-phase/quadrature (I/Q) signals; identifying signal bandwidth of the I/Q signals according to at least two signal identification templates and outputting the synchronized signal flows after a successful identification. A system for adaptively identifying signal bandwidth is also disclosed. The present invention can be compatible with at least two bandwidth modes, and the software can automatically perform identification and switch of the modulation bandwidth, when manual invention is not necessary and the operation is simple.

Abstract: A technology is provided capable of improving the efficiency of an OFDM system by obtaining the performance in Bit Error Rate (BER) in a wireless communication using OFDM and determining the minimum FFT input bit that produces a SNR difference of 0.1 dB or below with respect to a theoretical BER graph at a desired performance.

Abstract: Certain aspects of the present disclosure relate to a method and an apparatus for unified iterative demodulation-decoding that can be employed in both multiple-input multiple-output (MIMO) and non-MIMO wireless systems.

Abstract: A system for correcting gain imbalance and phase imbalance between first (IOUT) and second (QOUT) signals which are 90° out of phase, including circuitry for estimating the phase mismatch (?) and gain mismatch (?) between the first signal and the second signal signals in a plurality of frequency bands. An inverse fast Fourier transform is performed on each of a number of arrays of the phase mismatch estimates and the gain mismatch estimates to generate correction filter coefficients (h[N]) for a N tap correction filter. The N tap correction filter filters an uncorrected value of the second signal to generate a corrected value of the second signal.

Abstract: There are provided a method and apparatus for transmitting and receiving signals in the same frequency band at the same time. A signal is received using a dual polarization antenna, the main axis of the polarization of the reception signal is predicted by performing adaptive polarization tracking, and polarization filtering is performed in order to remove interference. A signal is transmitted through a polarization completely orthogonal to the tracked polarization. In accordance with the present invention, in a wireless communication system, signals can be transmitted and received in the same frequency band at the same time.

Abstract: A decoding apparatus including an operation unit to calculate a branch metric between first and second instants of time based on receiving likelihood data and an anterior likelihood, and to use, in a state transition in a butterfly represented by first and second states at the first instant of time and third and fourth states at the second instant of time, a first anterior cumulative metric for the first state, a second anterior cumulative metric for the second state and a first difference based on the branch metric between the first state and the third state and on a second difference between the first anterior cumulative metric and the second anterior cumulative metric to calculate a third anterior cumulative metric for the third state and a fourth anterior cumulative metric for each butterfly and at each instant of time, and a storage unit to store the second difference.

Abstract: A digital receiver includes a radio frequency analog front end, a digital processing unit, a plurality of cascaded amplifier stages configured to receive output of the radio frequency analog front end, a first analog to digital converter configured to convert an analog signal output from the plurality of cascaded amplifier stages into a digital signal output to the digital processing unit, a first received signal strength indicator unit configured to receive outputs of each of the plurality of cascaded amplifier stages and output signal to the digital processing unit, a second received signal strength indicator unit configured to receive output of at least one amplifier stage in the plurality of cascaded amplifier stages, and a received signal strength indicator detection unit configured to activate and to deactivate digital units according to a comparison of output from the second received signal strength indicator unit to a predetermined threshold.

Abstract: Methods and apparatus for processing multichannel signals in a multichannel receiver are described. In one implementation, a plurality of demodulator circuits may provide a plurality of outputs to a processing module, with the processing module then simultaneously estimating noise characteristics based on the plurality of outputs and generating a common noise estimate based on the plurality of outputs. This common noise estimate may then be provided back the demodulators and used to adjust the demodulation of signals in the plurality of demodulators to improve phase noise performance.

Abstract: Some demonstrative embodiments include devices, systems and/or methods of combining received wireless communication signals. For example, a device may include a radio-frequency (RF) combiner to combine first and second wireless communication RF signals of a wireless communication frame received via first and second respective antennas, into a combined signal; and a base-band phase estimator to estimate a phase difference between the first and the second antennas, and to provide to the RF combiner a feedback corresponding to the phase difference, wherein the radio-frequency combiner is to combine the first and the second RF signals according to the feedback.

Abstract: A method includes determining a mean square error ?h2 of an estimate h of a communication channel, and receiving a data symbol y. The received data symbol y corresponds to a data symbol x transmitted over the communication channel. The method also includes determining a likelihood value for a bit in the transmitted data symbol x. Determining the likelihood value for the bit in the transmitted data symbol x includes calculating a quantity according to ? - ? y - hx ? 2 ? z 2 + ? h 2 ? ? x ? 2 , where ?z2 is a noise power associated with the communication channel. The method also includes calculating the likelihood value for the bit in the transmitted data symbol x as a function of the calculated quantity.

Abstract: Techniques for transmitting data over a communications channel are generally described. A value of a property of an inverse of a channel matrix corresponding to the communications channel may be calculated and compared to a threshold value. If the value of the property a first one of greater than or less than the threshold value, at least one transmit message may be altered using a vector perturbation technique to generate data symbols and the data symbols may be precoded using a channel inversion technique to generate precoded data symbols. If the value of the property is the other of greater than or less than the threshold value, the at least one transmit message may be precoded using a channel inversion technique to generate precoded data symbols.

Abstract: A transmitted OFDM signal is detected in a receiver of a wireless communication system. The receiver has at least two receiver branches, each comprising an antenna, a front end receiver, a Discrete Fourier Transform unit, and a channel estimator. The receiver further comprises a detector for detecting received data symbols. The method comprises the steps of determining a system bandwidth associated with the transmitted signal; comparing the determined system bandwidth with a predetermined value; determining, if the system bandwidth is lower than the predetermined value, channel estimates separately for each branch, and detecting received data symbols from the received signals and corresponding channel estimates; and calculating, if the system bandwidth is higher than the predetermined value, a weighted sum of signals from each branch, determining a combined channel estimate, and detecting received data symbols from the weighted sum and the combined channel estimate.

Abstract: A method includes: demodulating a signal transmitted by a first source end that is received to obtain a first log-likelihood ratio; demodulating a signal transmitted by a second source end that is received to obtain a second log-likelihood ratio; demodulating a signal transmitted by a relay node that is received to obtain a third log-likelihood ratio; based on an exclusive OR feature of network coding, processing the first log-likelihood ratio, the second log-likelihood ratio, and the third log-likelihood ratio to obtain a posterior log-likelihood ratio of the first source end; and decoding the signal transmitted by the first source end that is received by using the posterior log-likelihood ratio of the first source end.

Abstract: Apparatus and methods for use in a wireless communication system are disclosed for recovery of timing tracking in a device, such as a wireless transceiver, after decoding errors occur due to incorrect timing tracking. In particular, the disclosed methods and apparatus recover timing tracking by monitoring a decoded signal in the transceiver for decoding errors occurring during a first frame, determining whether a number of decoding errors is greater than a predetermined amount, reacquiring a first pilot channel at a start of a subsequently received second frame when the number of decoding errors is determined to be greater than the predetermined amount, and resetting timing tracking of the transceiver based on the reacquired first pilot channel.

Abstract: Data communication apparatus comprising transmission means adapted to transmit data as the ratio of pairs of frequencies between objects that are moving relative to one another. It is particularly applicable to acoustic data communications at ultrasound frequencies in air.

Abstract: A circuit, use, and method for controlling a receiver circuit is provided, wherein a complex baseband signal is generated from a received signal, a phase difference between a phase of the complex baseband signal and a phase precalculated from previous sampled values is determined, the phase difference is compared with a first threshold, a number is determined by counting the exceedances of the first threshold by the phase difference, a number of the counted exceedances is compared with a second threshold, and the receiver circuit is turned off if the number of counted exceedances exceeds the second threshold within a time period.

Abstract: Provided is a relay node that performs network coding with respect to signals transmitted from a plurality of sources. The relay node may partition a plurality of constellation points into a plurality of subsets, generate a new constellation diagram based on respective characteristics among the plurality of subsets, and perform network coding based on the new constellation diagram.

Abstract: In a wireless near field communication (NFC) system, a target, such as a smart card, can communicate with an initiator, such as a card reader, by load modulating a radio frequency (RF) signal generated by the initiator. When two or more targets load modulate the RF signal generated, “collisions” can occur with the load modulation. Apparatus and methods detect the presence or absence of collisions in a lower layer or physical layer and report the presence of detected collisions to an upper layer for further handling.

Abstract: Systems and methods are provided for channel estimation using linear phase estimation. These systems and methods enable improved channel estimation by estimating a linear channel phase between received pilot subcarrier signals. The estimated linear phase can then be removed from the received pilot subcarrier signals. After the estimated linear phase is removed from the received pilot subcarrier signals, a channel response can be estimated. A final estimated channel response can be generated by multiplying the results of the linear channel estimation by the estimated linear phase.

Abstract: Provided is a method for configuring a transmission mode for a backhaul link transmission in a radio communication system including a relay station. The method comprises: a step in which a base station transmits, to the relay station, a relay-physical downlink control channel (R-PDCCH) containing backhaul control information; and a step in which the base station transmits, to the relay station, a relay-physical downlink shared channel (R-PDSCH) containing backhaul data, wherein the R-PDCCH is transmitted in one transmission mode selected from a plurality of predetermined transmission modes, and a reference signal transmitted through the R-PDCCH for the demodulation of the R-PDCCH is determined in accordance with said selected transmission mode.

Abstract: A desired signal and interfering signal are transmitted in the same timeslot and on the same frequency using an Adaptive Quadrature Phase Shift Keying (AQPSK) modulated carrier. When the Subchannel Power Imbalance Ratio (SCPIR) for the AQPSK modulated carrier is large and favors the interfering signal, SIC is used to cancel the interfering signal from the received signal. Following interference cancellation, the desired signal is demodulated using two different estimates of the channel and the demodulated soft bits from demodulated soft bits from each demodulation process are combined to obtain a combined estimate.

Abstract: A multichannel radio receiver is configured to define at least two channel plans, each channel plan having at least one channel. The channel plans may differ due to channel bandwidths, channel locations, channel number and/or channel spacings. At least a portion of a radio spectrum may be common to at least two of the channel plans. At least two decoders may operate simultaneously to decode different modulation schemes on each of the at least two channel plans. In one example, two channel plans overlap portions of the radio spectrum. Two different and complementary modulation schemes are used on the two channel plans, respectively. The complementary modulation schemes reject signals associated with the other. Accordingly, portions of the radio spectrum are used simultaneously by at least two channel plans and at least two modulation schemes, respectively.

Abstract: A method of demodulating a plurality of multiplexed modulation signals is provided, including: i) inputting the plurality of multiplexed modulation signals, each of which being outputted from a plurality of outputs of a communication partner, wherein each modulation signal in the multiplexed modulation signals includes a pilot symbol sequence consisting of a plurality of pilot symbols used for demodulation, ii) estimating respective channels of the multiplexed modulation signals based on one or more of the pilot symbol sequences; and iii) demodulating each modulation signal in the plurality of multiplexed modulation signals based on the channel estimation. Each of the pilot symbol sequences is inserted at a same temporal point in each modulation signal among the multiplexed modulation signals. The pilot symbol sequences are orthogonal to each other with zero cross correlation among the modulation signals in the multiplexed modulation signals, and each pilot symbol has a non-zero amplitude.

Abstract: Compressing a variable phase component of a received modulated signal with a second harmonic injection locking oscillator, and generating a delayed phase-compressed signal with a fundamental injection locking oscillator, and combining the phase-compressed signal and the delayed phase-compressed signal to obtain an estimated derivative of the variable phase component, and further processing the estimated derivative to recover data contained within the received modulated signal.

Abstract: A receiver and method for a transponder of a two-way automatic communications system (TWACS) used by an electrical utility in which analog outbound messages are sent from the utility to a consumer and inbound, reply messages are sent from the consumer to the utility. The receiver and method enable a transponder to detect the outbound messages and include A/D conversion and digital processing for demodulating a digitized signal and providing the outbound message.

Abstract: A circuit and a method for removing a frequency offset and a communication apparatus including the circuit, capable of removing the frequency offset by tracking rapidly and accurately in a payload section. A sequence of sample levels is obtained by sampling a frequency level of the baseband signal at every 0.5 symbol interval. Absolute values of differences between the frequency levels adjacent to each other at every 1 symbol are calculated as first difference absolute values. Absolute values of differences between the frequency levels adjacent to each other at every 1 symbol are calculated as second difference absolute values. When the first difference absolute values are greater than a predetermined first determination value or the second difference absolute values are less than a predetermined second determination value, the average value calculated is set as the frequency offset.

Abstract: A transmitter is configured to transmit a radio frequency (RF) signal to a receiver. The receiver is configured to receive the RF signal and decode data. Furthermore, a method of wireless communication is provided between the transmitter and the receiver, in which the transmitter transmits to the receiver the RF signal. A carrier phase of the RF signal is randomly converted. The receiver detects an envelope of the RF signal, and extracts data from the RF signal.

Abstract: The present invention provides a receiver, a transmitter, a transmitter feedback device, and corresponding methods. The feedback device includes: a multi-channel frequency selection band-pass circuit, configured to receive a multi-frequency band feedback signal, and output a feedback signal of each frequency band in a time-division manner; a feedback local oscillator, configured to provide feedback local oscillation corresponding to each frequency band in a time-division manner; a mixer, configured to mix the feedback signal of each frequency band from the multi-channel frequency selection band-pass circuit and the feedback local oscillation corresponding to each frequency band from the feedback local oscillator, and output an intermediate frequency signal of each frequency band in a time-division manner. A solution in which only one set of signal processing channels is used to process the signals of multiple frequency bands in the uplink, the downlink or both the uplink and downlink is provided.

Abstract: Systems and methods of performing ASK or QAM modulation with uneven distance between symbols are provided. Different bit positions mapped to such symbols are assigned to different receivers, with the result that there are different BER performances among bits sent from a transmitter to the different receivers. Bits for multiple receivers are mapped to a UASK constellation or a UQAM constellation without using superposition.

Abstract: The present disclosure provides a method of carrier phase error removal associated with an optical communication signal. The method includes estimating and removing a first phase angle associated with an information signal using coarse phase recovery, the information symbol being associated with a digital signal, the digital signal representing the optical communication signal; estimating a carrier frequency offset between a receiver light source and a transmitter light source by using the estimated first phase angle, the carrier frequency offset being associated with the information signal; removing carrier phase error associated with the carrier frequency offset; and estimating and removing a second phase angle associated with the information signal, the estimated second phase angle being based on the estimated first phase angle and the estimated carrier frequency offset.

Abstract: A novel and useful wideband FM demodulator operating across an 8 GHz IF bandwidth for application in low-power, wideband heterodyne receivers. The demodulator includes an n-stage ring oscillator that is injection locked to a wideband input signal. Locking to the input frequency, it divides the FM deviation by n, thereby facilitating as well as reducing the energy required for wideband demodulation. The quadrature-phased output of the ring oscillator is auto correlated using a low-power folded CMOS mixer capable of detecting FM up to 400 Mb/s over a 2-10 GHz IF frequency range.

Abstract: Provided is an apparatus and method for iteratively detecting and decoding a received signal in a wireless communication system. An apparatus for iterative detection and decoding (IDD) in a wireless communication system may determine a predetermined group to be updated in a first soft decision sequence, may transmit detection control information of the determined group, and may generate a second soft decision sequence based on a detection operation result of a predetermined received signal portion that is extracted based on the detection control information.

Abstract: A distortion compensator compensates for distortion of a signal caused by an amplifier. A storage section stores a plurality of compensation coefficients used for distortion compensation. A selection section selects a compensation coefficient corresponding to an index value indicative of a power level of the signal from among the plurality of compensation coefficients. The selection section determines whether or not the power level is higher than a threshold, and uses, based on a determination result, a first index value calculated without using a logarithmic operation or a second index value calculated by using a logarithmic operation.

Abstract: An OFDM receiver receives OFDM symbols in the frequency domain and comb filters and then punctures the OFDM symbols to leave symbols with actual pilot information and with null values at the data symbols. The receiver provides the punctured OFDM symbols to an OFDM symbol queue. A virtual pilot interpolator is coupled to the punctured OFDM symbol storage to generate virtual pilot information introduced to OFDM symbols. The interpolator may be a two dimensional Wiener filter. The receiver also includes a time domain channel estimator that processes a first OFDM symbol including virtual pilot information to generate a channel impulse response for the first OFDM symbol. A frequency equalizer equalizes the OFDM symbol in response to the channel impulse response for the first OFDM symbol.

Abstract: A broadcast receiver suitable for receiving broadcast signals transferred by use of signal format of IBOC system. The broadcast receiver comprises a receiving means that holds information related to channels that can be acquired by a digital signal decoding process. If information related to a channel is to be used and is held by the information holding means, then it is used.

Abstract: A receiver receives, using a plurality of antennas, a multiplexed signal that includes (i) a first OFDM modulation signal with a subcarrier carrying a symbol including multiplex information and a subcarrier carrying a pilot symbol and a subcarrier carrying a data symbol and (ii) a second OFDM modulation signal with a subcarrier carrying a symbol including multiplex information and a subcarrier carrying the pilot symbol and a subcarrier carrying the data symbol. A decoder uses the symbol including multiplex information and decodes the data symbol.

Abstract: Apparatuses, systems, and methods are directed to maintaining optimal carrier tracking performance in view of operating conditions that prevail. Such configurations employ a phase lock loop that configured to generate an estimated phase error value, a variance module configured to calculate a phase noise variance based on the estimated phase error value, and a loop control bandwidth module that calculates a loop bandwidth value based on a detected lower phase noise variance, generates modified loop filter values in accordance with the calculated loop bandwidth value, and updates the phase lock loop with the modified loop filter values. During subsequent iterations, the modified loop filter values are incrementally adjusted along a particular direction until the phase noise variance increases at which point the modified loop filter values are incrementally adjusted in an opposite direction to converge on an optimal loop bandwidth value.

Abstract: One or more embodiments describe a decision feedback equalizer utilizing symbol error rate biased adaptation function for highly spectrally efficient communications. A method may be performed in a decision feedback equalizer (DFE). The method may include determining values of tap coefficients used by the DFE based. The tap coefficients may be determined based on an error signal that is based on an estimated inter-symbol-correlated (ISC) signal. The tap coefficients may be determined based on a set of error vector(s), where each error vector in the set represents a difference between estimated symbols generated in the receiver and expected symbols. Determining the values of the tap coefficients may include using a symbol error rate function that estimates the actual symbol error rate in the receiver, wherein the symbol error rate function receives as input the set of error vector(s).