Abstract: A communications system receives a modulated signal that carries encoded communications data. An adaptive filter has a plurality of non-adaptive and adaptive filter taps with weighted coefficients and an adaptive gain circuit for updating the adaptive gain of the adaptive filter responsive to a received state of a modem or the type of modulation used by communications system. A demodulator and decoder receive the filtered output signal from the adaptive filter and demodulate and decode the signal to obtain the communications data.

Abstract: The present invention provides a system and method for performing ranging operations in a able modern system. In accordance with embodiments of the present invention, transmission times, transmission power levels, transmission carrier frequencies, and pre-equalization parameters are adjusted to provide for robust operation of the cable modem system. More particularly, iterative processing steps are used to provide coefficient ordering, scaling, and aligning between the multiple cable modems and the cable modem termination system present in a cable modern system.

Abstract: A coaxial network communication node receives multimedia content with one or more other nodes in a Multimedia over Coax Alliance (MoCA®) coaxial network. The node determines a delay-spread of a coaxial channel based on a probe received from a transmitting node during a link-maintenance operation (LMO) cycle. The probe is stored and reused during the LMO until the channel-shortening TEQ filter converges. The node configures a channel-shortening time-domain equalizer (TEQ) filter to effectively shorten the channel and instructs the transmitting node to shorten a length of a cyclic prefix for subsequent packet-based transmissions.

Abstract: Method and apparatus for data reception are provided, retrieving digital values transmitted through a cable. In a data receiver, an equalizer equalizes an input signal based on a boost value to generate an equalized signal, and a data extractor samples the equalized signal to extract output values from each symbol period. The data extractor detects signal quality of the equalized signal to adjust the boost value accordingly. An optimal time point is detected within one symbol period where an output value is an ensured valid, and variation rate of the optimal time point is counted as an inverse indicator of the signal quality.

Abstract: A communications device includes a signal input for receiving both wideband and in-band, narrowband communication signals having wideband communications data that is transmitted over a wideband communications channel and narrowband communications data that is transmitted within an in-band, narrowband channels over the same wideband communications channel. A circuit splits the communications signals into a wideband signal channel and narrowband signal channels. A narrowband filter within the wideband signal channel filters the wideband communications signal and removes any narrowband communications signals. A demodulator within the wideband signal channel demodulates the filtered wideband communications signal to obtain any wideband communications data. An in-band, narrowband demodulators are positioned within the narrowband signal channels and demodulate the narrowband communications signals to obtain any narrowband communications data.

Abstract: A system and method of adapting a FIR filter with a mixed minimum-mean-square-error/zero-forcing adaptation is disclosed. A channel response module attempts to approximate a noiseless component of the channel response. The output of the channel response module is utilized to adapt a FIR filter module. In some embodiments, a combination of the output of the channel module and the noiseless channel output is utilized to adapt the FIR filter. In some embodiments, a second FIR filter module is utilized to process the noiseless channel output, which is then compared to the target response to generate an error signal, which may be used to adapt both the first and second FIR filter modules.

Abstract: A signal receiver inputs a signal, computes a set of equalizer tap values during a signal acquisition phase by applying an algorithm iteratively to a given set of training data contained within the signal, and uses the set of equalizer tap values to perform signal equalization during the signal acquisition phase. The algorithm includes computing and applying phase correction to the pre-equalized signal at each adaptation step to correct for phase error related to the main path only, of the input signal.

Abstract: A system and method are provided for removing quadrature imbalance errors in received data. The method accepts an unbiased training sequence in a quadrature demodulation receiver. An unbiased training sequence has a uniform accumulated power evenly distributed in a complex plane, and includes predetermined reference signals (p) at frequency +f and predetermined mirror signals (pm) at frequency ?f. The unbiased training sequence is processed, generating a sequence of processed symbols (y) at frequency +f, representing complex plane information in the unbiased training sequence. Each processed symbol (y) is multiplied by the mirror signal (pm), and an unbiased quadrature imbalance estimate Bm is obtained at frequency (?f). Using quadrature imbalance estimates, channel estimates, and processed symbols, an imbalance-corrected symbol can be generated.

Abstract: A system and method are provided for channel equalization using a combination of frequency and phase compensation. The method receives a serial data stream input, and parallel processes the data stream input through a first and second path. The first path has a first frequency response, and the second path has a second frequency response, higher than the first frequency response. Signals are combined from the first and second paths, creating a frequency compensated signal. Then, the frequency compensated signal is parallel processed through a third path having a first time delay, and a fourth path having a fourth time delay, greater than the third time delay. The signals from the third and fourth paths are combined, created a phase compensated signal. In one aspect, the phase compensated signal is amplified, creating a voltage limited output signal.

Abstract: A method and apparatus for generating a TSC in a communication system are provided, in which a pair of sequences A and B having auto-correlation and cross-correlation properties are generated and the TSC is generated by inserting guard sequences Z each having z zero symbols in the most significant bits of the sequences A and B.

Abstract: A method and apparatus for joint training of an analog equalizer (AEQ) and an analog echo canceller (AEC) is described. In one embodiment, which both the AEQ and AEC process an input analog signal in the analog domain. In one embodiment, the method includes joint training the AEQ and the AEC using independent analog error signals.

Abstract: A channel equalizer includes a first transformer, an estimator, an average calculator, a second transformer, a coefficient calculator, a compensator, and a third transformer. The first transformer converts normal data into frequency domain data, where a known data sequence is periodically repeated in the normal data. The estimator estimates channel impulse responses (CIR) during known data intervals adjacent to each normal data block. The average calculator calculates an average value of the CIRs. The second transformer converts the average value into frequency domain data. The coefficient calculator calculates equalization coefficients using the average value, and the compensator compensates channel distortion of each normal data block using the coefficients. The third transformer converts the compensated data block into time domain data.

Abstract: A wireless communication system is provided that detects a frequency burst (FB) through analysis of the autocorrelation function of received signals. The system can accommodate the relatively large frequency offsets that are associated with less expensive reference frequency crystals. The system employs a multi-mode filter including an FB filter and a channelization filter. In one embodiment, the FB filter is employed until an FB is located and then, once the FB is located, the channelization filter is employed to receive signals.

Abstract: A soft-bit de-mapping device and method of generating soft bits for decoding quantizes a log-likelihood ratio (LLR) value for a received value using functions bits and channel parameter bits to generate the soft bits. The function bits are generated by quantizing an LLR function for the received value, which includes modifying an original curve of the LLR function to a modified curve such that a segment of the original curve with the lowest slope is protected in the modified curve for a fixed equal quantization step-size. The channel parameter bits are generated by quantizing a channel parameter for the received value to generate channel.

Abstract: A novel and useful apparatus for and method of nonlinear adaptive phase domain equalization for multilevel phase coded demodulators. The invention improves the immunity of phase-modulated signals (PSK) to intersymbol interference (ISI) such as caused by transmitter or receiver impairments, frequency selective channel response filtering, timing offset or carrier frequency offset. The invention uses phase domain signals (r, ?) rather than the classical Cartesian quadrature components (I, Q) and employs a nonlinear adaptive equalizer on the phase domain signal. This results in significantly improved ISI performance which simplifies the design of a digital receiver.

Abstract: There is provided a jitter amplifier circuit for amplifying jitter included in an input signal. The jitter amplifier circuit includes a distorting circuit that receives the input signal, and distorts a waveform of the input signal so as to generate a harmonic component of the input signal, and a filter that passes, out of the distorted signal output from the distorting circuit, a harmonic component of a certain order which is determined in accordance with an amplification ratio of amplifying the jitter.

Abstract: A method applied to an equalizer includes receiving an input data-stream having a training sequence component with a first number of symbols and a data component with a second number of symbols, wherein the first number plus the second number equals a third number; when a symbol number is not greater than the first number, training the training sequence component to generate a first trained coefficient set; when the symbol number is between the first number and the third number, recycling the training sequence component to generate a recycled training sequence component, and training the recycled training sequence component to generate a second trained coefficient set; storing the input data-stream to generate a delayed input data-stream when the symbol number is not greater than the third number; and applying the second trained coefficient set to the equalizer when the symbol number is greater than the third number.

Abstract: In described embodiments, an adaptive equalizer employed by a receiver in a communication channel, such as Fiber Channel, employs pattern recognition. When a repeating pattern, such as an IDLE or ARBFF pattern, is employed by a standard to, for example, maintain a communication link, an equalizer of the receiver might adaptively set its equalizer parameters based on characteristics of the signal energy of the repeating pattern rather than adaptively set its equalizer parameters based on characteristics of the signal energy of generally random user data carried on the link. Pattern recognition by the receiver allows for maintaining adaptive equalizer parameters at settings preferred for data detection of the typical random data, improving data detection performance of the receiver when the channel transitions from a preset or synchronization repeating pattern to a user random data pattern.

Abstract: Various systems and methods are described for performing fractionally spaced time domain equalization (TEQ). One embodiment is a method implemented in a communication system for training a fractionally spaced time domain equalizer (TEQ). The method comprises performing an initialization phase, averaging a received signal in the system to reduce effects of noise in a channel, determining a channel estimate, and aligning an ideal reference signal with the received signal. The method further comprises updating a target response filter according to a non-integer multiple of a base sampling rate, determining an adaptation error based on useful information both inside and outside a Nyquist band of the TEQ, and updating the TEQ according to the adaptation error.

Abstract: A computer system that detects for a PCI Express compliant endpoint device is described. Specifically, the computer system clocks transmit and receive circuits at a first frequency and initiates a training sequence. If the endpoint device successfully trains at the first frequency, the endpoint device is PCI Express compliant. Otherwise, the computer system initiates another training sequence at a second frequency.

Abstract: A method and an apparatus for slicing a multilevel analog signal using a two-level slicer having one threshold level to generate an analog error signal. The method may be performed by delaying a received multilevel analog signal in a plurality of serial analog stages (n), further delaying a multilevel analog signal tapped from stage n, combining the further delayed signal from stage n with an analog error signal e(t) to provide an analog weighting function Wn, wherein the combining of the delayed signal from stage n with Wn results in a plurality of signals XnWn, summing the plurality of signals XnWn, slicing a multilevel analog signal resulting from the summing of the plurality of signals XnWn using one threshold level to generate the analog error signal e(t), and combining the delayed signal from stage n with Wn.

Abstract: Systems and methods according to the present invention provide channel estimation methods, systems and devices which determine a coarse channel estimate (40) and a fine channel estimate (66). The coarse channel (40) estimate can be determined based on the channel estimation sequence transmitted to the receiver and then used to detect header symbols. The header symbols can be used to calculate additional channel estimates which can then be combined with the coarse channel estimate (40) to determine a fine channel estimate (66).

Abstract: A time-of-arrival (TOA) estimation method for multi-band orthogonal frequency division multiplexing (MB-OFDM) signals uses a simple equally-spaced channel model to recover the impulse response of the wireless channel, and locates the delay of the first channel path by minimizing the energy leakage from the first channel path. The TOA is estimated based on the delay. Such a method does not require channel information for TOA estimation at the receiver and does not require modification of the receiver structure. The method also avoids a sub-optimal solution known to occur in maximum likelihood (ML) estimation.

Abstract: A frequency response measurement circuit includes a generation circuit operative to provide an input signal having a voltage and programmable frequency characteristics in response to a frequency control signal. A decision circuit is coupled to the generation circuit and is operative to sample the input signal at predetermined intervals in response to a sampling clock signal and determine the amplitude characteristics of the input signal relative to a variable threshold signal. A control circuit is coupled to the decision circuit, and is operative to determine the frequency response characteristics of the input signal at varying frequencies and threshold voltages in response to the frequency control signal.

Abstract: In one embodiment, the present invention includes a method communicating control information for an external adaptive equalization process for a channel coupled between a transmitter and a receiver from an external agent. In this way, the external agent may control tap settings of an equalizer based on feedback information from the receiver responsive to a data pattern generated and transmitted by the transmitter. Other embodiments are described and claimed.

Abstract: A parallel equalizer for a DS-CDMA UWB system and method thereof are provided. The parallel equalizer includes: a filter block for filtering a training input signal in a ‘training mode’, and filtering the plurality of input signals in parallel in a ‘symbol decision mode’; a symbol decision block for obtaining a symbol error based on a output from the filter block and a training symbol in the ‘training mode’, and estimating a transmission symbol for each of the input signals in the ‘symbol decision mode’, obtaining an error of one among the estimated transmission symbols for a symbol error calculating input signal; and an weight update block for updating a filter tap coefficients of the filter block based on the training input signal or the symbol error calculating input signal and the symbol error and transmitting the updated filter tap coefficients into the filter block.

Abstract: An OFDM (orthogonal frequency-division multiplexing) receiver circuit can include a GI (Guard Interval) combiner circuit that is configured to adaptively combine data in the GI of an OFDM formatted signal with data included in a predetermined section of an active OFDM symbol.

Abstract: A module and kit for coupling at least one telephone service signal to at least one telephone device over a wiring. The network includes: a wiring having at least two conductors for carrying multiple time-domain multiplexed digitized voice channels; an exchange side device coupled to the wiring and operative to couple at least one telephone service signal to at least one digitized voice channel; and at least one subscriber side device coupled to the wiring and operative to couple the at least one telephone device to at least one digitized voice channel.

Abstract: Provided is a method of selecting an algorithm in a wireless receiver which supports a plurality of algorithms, more particularly, a method of selecting a suitable algorithm which is adaptive to changes in channel environment and satisfies requirements of applications, using information which is available in the wireless receiver. The algorithm selection method includes: calculating a measure value for selecting an algorithm on the basis of information obtained from the wireless receiver; comparing the measure value with at least one threshold value, and selecting an algorithm that is to be applied to a received packet, from among the plurality of algorithms, according to the result of the comparison; and decoding the received packet using the selected algorithm, wherein the at least one threshold value is adaptively updated on the basis of the information obtained from the wireless receiver.

Abstract: A method and system for decoding data received from a channel experiencing two-dimensional inter-symbol interference, as well as systems implementing such a decoding method and system, are disclosed. The method includes an iterative multi-strip equalization method that receives a plurality of channel values associated with a plurality of locations in a plurality of rows of a matrix, computes initial probability values based upon those channel values, applies a BCJR algorithm to symbol probability values based upon bands of rows of the initial probability values, and resolves the results of applying the BCJR algorithm to arrive at a plurality of bands of rows of revised probability values, which are subsequently combined/substituted with one another. The process iteratively repeats until the revised probability values attain a sufficient degree of convergence. By utilizing data from overlapping bands to perform the BCJR algorithm, ISI in both dimensions is addressed.

Abstract: Systems and techniques relating to processing information received from a spatially diverse transmission. In some implementations, a method comprises: obtaining a received signal that was transmitted over a wireless channel using spatially diverse transmission, the received signal comprising multiple subcarriers; and recursively computing a signal-to-noise-ratio (SNR) of the received signal while receiving channel response information of the wireless channel derived from the received signal; wherein the recursively computing comprises recursively updating a diagonal kernel matrix, the method further comprising generating an equalization matrix from the recursively updated diagonal kernel matrix, the equalization matrix being useable in equalizing the received signal across the multiple subcarriers.

Abstract: A channel estimator for use in a DVB-T system is capable of high Doppler performance without incurring restrictive delay spread limitations, in a hardware efficient manner. A first channel impulse response is generated that has ambiguity due to under-sampling in the frequency domain. A filter is then used to filter scattered pilots to generate a mask that is capable of resolving the ambiguities. In at least one approach, a finite impulse response filter is used during the mask generation process to generate a snapshot of the channel frequency response in non-real time. In another approach, an infinite impulse response filter is used during the mask generation process to generate a channel frequency response in real time.

Abstract: First and second data is transmitted simultaneously by modulating a first set of signal constellation points, corresponding to the first data, with second data thereby creating a second set of constellation points. The second set of constellation points comprises two subsets corresponding to two values of the first data. The constellation points are selected such that the minimum distance between the first and second subsets is not less than the minimum distance between the constellation points of the first set of constellation points.

Abstract: A decision feedback equalizing apparatus selectively using a feedback filter and a method thereof are provided. The apparatus includes: an equalizing unit including a feed forward filter (FFF) for correcting a distorted transmission channel by receiving a match-filtered signal and a feedback filter (FBF) for reducing inter symbol interference ISI of the corrected transmission channel for driving only the FFF in a blind mode and driving the FFF and the FBF in a decision directed mode; a diverge/converge determining unit for determining whether the decision feedback equalizing apparatus is diverged or converged using a unit square error obtained through a least unit square algorithm; and a filter controlling unit for controlling the equalizing unit in a blind mode if the decision feedback equalizing apparatus is determined as divergence, and for controlling the equalizing unit in a decision directed mode if the decision feedback equalizing apparatus is determined as convergence.

Abstract: Briefly, in accordance with one or more embodiments, parallel DFE processing may be utilized for single carrier systems that employ cyclic prefixes. The achieved parallelism allows working at contemporary clock rates that are significantly lower than the required sampling rate at high bandwidth systems such as 60 GHz transmissions.

Abstract: Equalization of an incoming data signal can be controlled by sampling that signal at times when data values in that signal should be stable (“data samples”) and when that signal should be in transition between successive data values that are different (“transition samples”). A transition sample that has been taken between two successive differently valued data samples is compared to a reference value (which can be one of those two data samples). The result of this comparison can be used as part of a determination as to whether to increase or decrease equalization of the incoming data signal.

Abstract: A joint detection system and associated methods are provided. The joint detection system is configured to perform joint detection of received signals and includes a joint detector accelerator and a programmable digital signal processor (DSP). The joint detector accelerator is configured to perform front-end processing of first data inputted to the joint detector accelerator and output second data resulting from the front-end processing. The joint detector accelerator is further configured to perform back-end processing using at least third data inputted to the joint detector accelerator. The programmable DSP is coupled to the joint detector accelerator, and the programmable DSP is programmed to perform at least one intermediate processing operation using the second data outputted by the joint detector accelerator. The programmable DSP is further programmed to output the third data resulting from the intermediate processing operation to the joint detector accelerator.

Abstract: Messages transmitted between a receiver and a transmitter are used to maximize a communication data rate. In particular, a multicarrier modulation system uses messages that are sent from the receiver to the transmitter to exchange one or more sets of optimized communication parameters. The transmitter then stores these communication parameters and when transmitting to that particular receiver, the transmitter utilizes the stored parameters in an effort to maximize the data rate to that receiver. Likewise, when the receiver receives packets from that particular transmitter, the receiver can utilize the stored communication parameters for reception.

Abstract: In certain embodiments, an equalization device for a wireless communication receiver includes multiple adjusting means coupled between corresponding multiple weighting means and a combining means. The multiple weighting means performs a weight process on a received multipath signal to obtain multiple weight results, respectively, according to a plurality of adjustable weight coefficients. The multipath signal includes a known training sequence and user data that may both experience channel fading. The adjusting means compares the weight results of the known training sequence with respective multiple known reference signals, and respectively adjusts the weight coefficient of each weighting means by utilizing the comparison results so that the weighting means weight the user data by utilizing the adjusted weight coefficient. The combining means combines the weight results of the user data to obtain a combined equalization signal.

Abstract: A channel memory length selection method for wireless communication systems is provided. The method comprises estimating an initial channel impulse response (CIR) for the wireless communication system; determining a first refined CIR with a first group of taps and a second refined CIR with a second group of taps based upon the initial CIR, number of the second group of taps being less than number of the first group of taps; and selecting either the number of the first group of taps or the number of the second group of taps as the channel memory length according to an energy concentration criterion in regard to the first refined CIR and the second refined CIR.

Abstract: Advance training information is provided to a receiving Home network station via auxiliary coding, synchronized and/or included in the relevant Ethernet type packet. The advance training information may be, e.g., past equalizer, timing recovery circuit, AGC circuit, echo canceler values resulting from the reception of a previous frame. The training information may be, e.g., an early identity of the source of the packet, with a subsequent lookup performed by the receiving station for predetermined training value(s), or the training values themselves may be transmitted to the home network receiver via auxiliary coding. The auxiliary coding information may be transmitted before and/or during the frame training period of the relevant frame.

Abstract: The present invention is related to an adaptive equalizer comprising multiple tuning circuits that generate tuning signals. Each tuning signal can typically induce higher frequency gain up to a limited level, e.g. +5 dB, at the upper data frequency for compensation of high frequency losses in the connected transmission channel. Several tuning signals can tune one adaptive amplifying compensation stage. In its adaptive amplifying compensation stage the tuning signal can generate through its tuning function, non-linear small-signal and large-signal transfer behavior. However, by limiting the amount of higher frequency gain to maximum +8 dB per tuning function, and by having only one tuning function active at a time the resulting deterministic fitter remains tolerable. Several adaptive amplifying compensation stages introducing non-linear effects in the compensation behavior and their tuning functions are disclosed. Especially at low power supply voltage the merits of the present invention become apparent.

Abstract: A receiver device for use in a wireless communication system (20) includes a rake receiver (32) and an equalizer receiver (34). A controller (36) selects one of the rake receiver (32) or the equalizer receiver (34) for processing a received signal. In some situations, the rake receiver (32) will provide better performance. In other situations, the equalizer receiver (34) will provide better performance. One embodiment includes a plurality of equalizers (34A, 34B). One of the equalizers processes a data packet from a received signal while another one of the equalizers trains for processing a signal from a subsequent scheduled user. Another example embodiment includes controlling an equalizer length based on a delay span or another selected channel metric.

Abstract: Adaptive interference cancellation algorithm using speech mode dependent thresholds. A method of processing radio frequency (RF) bursts dependent on a speech mode associated with data contained within the RF burst is presented. Different voice modes, full rate, half rate, and adaptive multi-channel rates each may require different signal to noise ratio (SNR) conditions in order to be successfully processed. To improve the equalization, the SNR associated with the burst is estimated. Based on the SNR or other related conditions, a decision can be made as to whether or not an interference cancellation burst process should be implemented. For example, any one or more of SNR of the signal, a measure of colored noise within the signal, an indication whether the signal being noise limited or interference limited, and a channel profile of the signal may indicate the presence of interference requiring the cancellation of such interference.

Abstract: A digital demodulating apparatus comprises a tuner constituted by circuit elements to perform channel select processing to a signal; a demodulator that performs demodulation processing to a signal output from the tuner; a power supply unit that supplies a normal power to each circuit element, and supplies to the circuit element a test power different from the normal power, over a first time period in place of the normal power; a test noise measuring unit that measures the intensity of test noise contained in a signal to be output from the tuner, when the power supply unit supplies the test power over the first time period; a comparing unit that compares the intensity of the test noise measured by the test noise measuring unit with a noise reference value as a reference for updating of the normal power; and a power updating unit that updates the intensity of the normal power on the basis of a result of the comparison by the comparing unit.

Abstract: A channel equalizer includes a first transformer, an estimator, an average calculator, a second transformer, a coefficient calculator, a compensator, and a third transformer. The first transformer converts normal data into frequency domain data, where a known data sequence is periodically repeated in the normal data. The estimator estimates channel impulse responses (CIR) during known data intervals adjacent to each normal data block. The average calculator calculates an average value of the CIRs. The second transformer converts the average value into frequency domain data. The coefficient calculator calculates equalization coefficients using the average value, and the compensator compensates channel distortion of each normal data block using the coefficients. The third transformer converts the compensated data block into time domain data.

Abstract: Method and system for synchronizing a receiver in an Orthogonal Frequency Division Multiplexing (OFDM) system. The method comprises transforming (105) a received signal from the time domain into the frequency domain to produce a transformed signal. The method further comprises rotating (110) each set of ranging tones of the transformed signal in the frequency domain based on a corresponding tone index to produce a set of phase-rotated frequency domain received ranging tones that is equivalent to time domain shifted ranging signals. Each ranging tone is rotated iteratively over a predefined set of delay-values and each delay-value within the predefined set of delay-values ranges from zero to a predetermined time delay. Also, the method comprises computing (115) a detection metric corresponding to each delay-value within the predefined set of delay-values based on the set of phase-rotated frequency domain received ranging tones.

Abstract: Low power decision feedback equalization (DFE) through applying DFE data to input data in a data latch is disclosed. In one embodiment, a decision feedback equalization (DFE) system to remove a post cursor intersymbol interference (ISI) through feeding back previous data scaled with adaptive weights to the DFE system, with each slice of the DFE system may include a first set of decision feedback digital to analog converters (DACs) to generate a first DFE data obtained through the feeding back the previous data scaled with the adaptive weights and a first data latch to generate an output data of the each slice through applying the first DFE data to an input data of the each slice in the first data latch to remove a first delay caused by performing the applying the first DFE data to the input data of the each slice outside of the first data latch.

Abstract: A communication system receives a modulated signal that carries encoded communication data. An adaptive filter has a plurality of adaptive filter taps and weighted coefficients and a variable delay circuit operative before the adaptive filter taps for separating the spacing of multipath introduced by adaptive filter and producing a filtered output signal with improved multipath performance. A demodulator and decoder receive the filtered output signal from the adaptive filter and demodulate and decode the signal to obtain the communications data.

Abstract: A system and method for enhancing the performance of an equalizer in a modem. Multiple techniques are disclosed which improve the modem performance. A first technique uses stored parameters for each burst from each remote site to demodulate a received data stream. A second technique compensates for the gain droop caused by storing parameters across each burst. A third technique minimizes errors caused by adapting the equalizer coefficients for each data burst by analyzing the SN ratio and error rate of the received burst. A fourth technique improves the convergence of the equalizer by using a two-part preamble, whereby both parts are transmitted using different modulation techniques. A fifth technique is provided which performs a soft reset of the modem without performing a complete reset of the modem. A sixth technique determines a modem adaptation factor based on the expected modulation type of an incoming burst transmission.