Abstract: Techniques for recovering a desired transmission in the presence of interfering transmissions are described. For successive equalization and cancellation (SEC), equalization is performed on a received signal to obtain an equalized signal for a first set of code channels. The first set may include all code channels for one sector, a subset of all code channels for one sector, multiple code channels for multiple sectors, etc. Data detection is then performed on the equalized signal to obtain a detected signal for the first set of code channels. A signal for the first set of code channels is reconstructed based on the detected signal. The reconstructed signal for the first set of code channels is then canceled from the received signal. Equalization, data detection, reconstruction, and cancellation are performed for at least one additional set of code channels in similar manner.

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 method comprises performing a first pass test over a plurality of sets of equalization coefficients to filter the plurality of sets of equalization coefficients to produce one or more filtered sets of equalization coefficients. Each filtered set of equalization coefficients meets a first predetermined threshold. The method also comprises performing a second pass test over the one or more filtered sets of equalization coefficients to determine a final set of equalization coefficients that meets a second predetermined threshold. The second pass test produces more accurate results than the first pass test.

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: Circuits and methods are provided for efficient feed-forward equalization when sample-and-hold circuitry is employed to generate n time-delayed versions of an input data signal to be equalized. To equalize the input data signal, m data signals are input to m feed-forward equalization (FFE) taps of a current-integrating summer circuit, wherein each of the m data signals corresponds to one of the n time-delayed versions of the input data signal. A capacitance is precharged to a precharge level during a reset period of the current-integrating summer circuit. An output current is generated by each of the m FFE taps during an integration period of the current-integrating summer circuit, wherein the output currents from the m FFE taps collectively charge or discharge the capacitance during the integration period. A gating control signal is applied to an FFE tap during the integration period to disable the FFE tap during a portion of the integration period in which the data signal input to the FFE tap is invalid.

Abstract: Systems and techniques for equalization of a response of a receiver. In one embodiment, a response of a device to a known signal is measured to generate a measured signal. A processor is operated to apply an initial weighting to the measured signal and the known signal. The processor is operated to iteratively perform the operations of constructing an equalizer based on the weighted signals, testing the performance of the equalizer on the measured signal, and adjusting weighting applied to the measured signal and the known signal, until the performance of the equalizer on the measured signal meets a predetermined criterion.

Abstract: A communication receiver including a time domain receive filter to provide a filtered output, the filtered output including colored noise. The receiver also includes a frequency domain, fractionally-spaced equalizer (FSE) unit to receive the filtered output from the receive filter. The FSE unit determines a separate weighting factor for each subcarrier, and the weighting factor is determined based on a noise variance of the subcarrier.

Abstract: A transmitter includes an equalizer for conditioning a data signal in response to a first and a second equalizer setting. The first and second equalizer settings are both associated with a selected point on a two-dimensional search grid. The search grid includes a first equalizer setting and a second equalizer setting for each point on the search grid. The transmitter transmits a data signal across a first channel medium using settings associated with a selected point on the search grid. A receiver analyzes the received signal from the transmitter to determine a signal quality metric. The search grid is used to select settings from neighboring points to produce signals that are evaluated to produce signal quality metrics. The results of the evaluations are used to efficiently search the search grid for optimum equalizer settings for the transmitter.

Abstract: Distortions of both amplitude and phase along a transmission line are compensated for by a trace canceller inserted between a transmitter and a receiver. The trace canceller has an equalizer that compensates for a trace length between the transmitter and the trace canceller. A variable gain amplifier between the equalizer and an output buffer has its gain controlled by an automatic gain control circuit that compares low-frequency swings of the input and output of the trace canceller. The gain of the variable gain amplifier is reduced to prevent the output buffer from saturating and clipping peak voltages on its output. Thus both the variable gain amplifier and the output buffer remain in the linear region. Training pulses from the transmitter are passed through the trace canceller without clipping of peak voltages, allowing the transmitter and receiver to adjust transmission parameters to best match the transmission line.

Abstract: Certain aspects of the present disclosure relate to a method for equalizing a pulse signal corrupted by a noise and by various channel effects for obtaining a signal based on the periodic-sinc pulse, which is suitable for Finite Rate of Innovation (FRI) processing applied at a receiver of a pulse-based communication system (e.g., an Ultra-Wideband receiver).

Abstract: The present invention is directed to a decision feedback equalizer that implements a multipath delay calculator to determine the delay between a line-of-sight component of a received data signal and a reflection of the line-of-sight component. The determined delay is used to control when decisions are used within the decision feedback equalizer so that the appropriate decisions are delayed until the reflection is received. In this way, the reflection can be substantially removed from the data signal using decisions that were generated when the line-of-sight component was received. Because the correction window is limited to the time when the reflection is received, the number of taps required to perform equalization is greatly reduced resulting in a decision feedback equalizer with less circuitry or logic.

Abstract: Estimating a channel impulse response (CIR) for a wireless transmission, for example a multimedia broadcast multicast services single frequency network (MBSFN) transmission, may be performed by a receiver of an wireless subframe, without requiring operational memory in excess of what is needed for CIR estimation of unicast signaling, while providing enhanced delay spread coverage. The wireless subframe may be a MBSFN subframe. The receiver may form an aggregate vector of pilot tones extracted from an OFDM reference symbol of an wireless subframe. The receiver may subsample the aggregate vector to obtain a plurality of sub-vectors each comprising a distinct subsampling phase. The receiver may process the plurality of sub-vectors using an inverse fast Fourier transform to obtain time domain representations of each of the sub-vectors. The receiver may combine the time domain representations in various ways to obtain a CIR estimate for the wireless subframe.

Abstract: Improved performance testing of a wireless device is disclosed. The system is particularly suited to testing devices having multiple antennas. The device under test (DUT) is placed in a reverberation chamber with antennas for transmission of a test signal to the DUT. The number of antennas deployed in the reverberation chamber and placement of those antennas is selected such that no line-of-sight transmission component exists from test system antenna to DUT antenna, and the number of antennas deployed in the reverberation chamber is greater than the spatial rank of the signal. The antennas are driven by a programmable channel emulator capable of generating fading, correlation, delay, Doppler and other channel condition phenomena. Furthermore, the antennas are driven individually by a plurality of independent fading processes.

Abstract: A method of initializing tap coefficients of an equalizer may include estimating impulse response coefficients of a channel through which a received signal traveled based on a known portion of the received signal. The method may also include loading the impulse response coefficients into a channel filter and generating a reference signal. The reference signal may be passed through the channel filter to build a training signal. Tap coefficients of the equalizer may be adjusted based on the training signal from the channel filter and on a delayed version of the reference signal.

Abstract: In at least some embodiments, a receiver for a wireless communication system is provided. The receiver includes an equalizer that provides an equalized channel matrix. The receiver also includes scaling logic coupled to the equalizer, the scaling logic selectively scales coefficients of the equalized channel matrix. The receiver also includes a decoder coupled to the scaling logic. The decoder decodes a signal based on the equalized channel matrix with scaled coefficients.

Abstract: Signal equalization is facilitated in a manner that provides for feedback operation with desirable equalization operation. As consistent with one or more embodiments, a sign is assigned to received signals by generating an output that is an absolute value of the received signals, and a comparator processes the output and to generate a signal having a voltage level limited to a predetermined value. A sign of a signal output by an equalizer is detected and used to assign a sign to the output of the comparator. A summation circuit sums the output of the equalizer with the output of the comparator, and provides the sum to the equalizer as an error signal. The equalizer modifies a frequency component of received signals based on the error signal.

Abstract: Methods and apparatus are provided for detecting and decoding adaptive equalization training frames (having a frame marker comprised of a string of binary ones and binary zeroes). Training frames are detected by shifting the received data; inserting at least one binary value at one end of the shifted received data to generate a modified version of the received data; applying a logic function to the received data and the modified version of the received data that identifies when corresponding bit positions have different values; and detecting the frame marker when an output of the logic function has a first binary value in an approximate middle of a string of a second binary value. The training frames are decoded using a distance between the approximate center of the frame marker and a predefined binary value in an output of the logic function.

Abstract: A method for processing a stream of a digital broadcast transmitter, the digital broadcast transmitter, a method of processing a stream of a digital broadcast receiver, and the digital broadcast receiver are provided. The method includes: configuring a stream including a slot to which mobile data is allocated; and encoding and interleaving the configured stream and outputting the encoded and interleaved stream. Each slot of the stream includes signaling data, and the signaling data includes a slot indicator indicating a type of a slot, and may include at least one of a backward training indicator and a forward training indicator according to a value of the slot indicator. Accordingly, information on an adjacent slot is efficiently used.

Abstract: An adaptive filter includes: a filter configured to perform a filtering process for an input signal with a filter coefficient set therein, and output the processed input signal as an output signal; a calculating unit configured to calculate a value indicative of an error between an amplitude of the output signal and a reference amplitude; an output unit configured to output a first constant as a parameter when the amplitude of the output signal is greater than the predetermined amplitude, the parameter used when updating the filter coefficient, and output a second constant as the parameter when the amplitude of the output signal is smaller than the predetermined amplitude; and an updating unit configured to update the filter coefficient with an update amount corresponding to the parameter and the value indicative of the error, such that the error is reduced.

Abstract: Apparatus and methods are provided to construct parameters associated with a precoder to a channel. Embodiments include apparatus and methods to apply a maximum a posteriori probability (MAP) equalization using offsets of signals introduced at a transmit end of a channel. Embodiments include apparatus and methods to construct a channel precoder based on using approximation of channel responses for a range of channel lengths.

Abstract: An equalization parameter analyzer includes a parameter section configured to acquire at least one current parameter for a wireless receiver and an analyzer section configured to compare the at least one current parameter with at least one corresponding previous parameter. Additionally, the equalization parameter analyzer also includes a coefficients section configured to initiate a generation of new equalizer coefficients in the wireless receiver based on a change between the at least one current and corresponding previous parameters that exceeds a predefined threshold. A method of equalization coefficients generation is also provided.

Abstract: Aspects of a method and system for channel estimation in a MIMO communication system with multiple RF chains for WCDMA/HSDPA may comprise receiving a plurality of communication signals from a plurality of transmit antennas. A plurality of vectors of baseband combined channel estimates may be generated based on phase rotation of the received plurality of communication signals. A matrix of processed baseband combined channel estimates may be generated based on the generated plurality of vectors of baseband combined channel estimates. A plurality of amplitude and phase correction signals may be generated based on the generated plurality of vectors of baseband combined channel estimates. An amplitude and a phase of at least a portion of the received plurality of communication signals may be adjusted based on the generated plurality of amplitude and phase correction signals, respectively.

Abstract: System and method for backoff correction of channel quality information (CQI). A correction factor is calculated based on a goodness measure such as packet error rate (PER). The selection of modulation and coding scheme (MCS) is made considering the channel quality information (CQI) adjusted by the correction factor. A meaningful goodness measure can be imposed if the goodness measure is very low. A different correction factor can be calculated for different confidence levels, MCSs and transmission modes.

Abstract: A system and method for wirelessly transmitting audiovisual information. Training information may be stored in a memory. A plurality of packets may be generated, including the training information. The plurality of packets may also include audiovisual information. The plurality of packets may include first information identifying a first training pattern of a plurality of possible training patterns. The first training pattern may specify one or more locations of the training information in the plurality of packets. The first information may be usable by a receiver to determine the first training pattern of the plurality of possible training patterns. The plurality of packets may be transmitted in a wireless manner.

Abstract: Techniques are described to adaptively adjust the equalizer settings of each transmitter in a transmitter-receiver pair. The transmitter-receiver pair can be used at least with implementations that comply with 40GBASE-CR4 or 100GBASE-CR10. For implementations that comply with 40GBASE-CR4, equalizer settings of four transmitters may be independently established.

Abstract: For a demand of high speed, low cost and low power loss short distance wireless communication, a high-speed sampling and low-precision quantification pulse ultra-wideband wireless communication method is provided. A baseband narrow pulse sequence is generated at a transmission end using the digital technology by the method, and is transmitted after modulating amplifying and filtering and amplifying at a reception end, after the digital-signal processing of synchronizing, channel estimating, related detecting, and channel decoding, tec, is performed for the quantified data, the transmission information is retrieved.

Abstract: In one embodiment, the method includes receiving a pilot signal from a terminal at a target antenna of the plurality of antennas of the network element, determining an uplink channel estimate for the target antenna based on the received pilot signal, and obtaining a calibration coefficient associated with the target antenna. The calibration coefficient is based on a channel estimate between the target antenna and a different one of the plurality of antennas. The method further includes beamforming a transmission to the terminal using at least the target antenna based on the determined uplink channel estimate and the obtained calibration coefficient.

Abstract: Wired and wireless communication networks can be subject to noise and interference resulting data corruption. In a communication system comprising a first network device and a second network device, the first and the second network devices can be configured for optimizing the data rate of the communication system. On receiving a multi-band signal at the first network device from the second network device during a channel adaptation mode, the multi-band signal can be split into a plurality of independent frequency band signals. A performance measurement of a first of the plurality of frequency band signals corresponding to a lowest frequency band signal can be calculated. Communication parameters can be determined for each of the plurality of frequency band signals based on the performance measurement of the first of the plurality of frequency band signals. The communication parameters can be provided from the first network device to the second network device.

Abstract: Described herein are a method, an apparatus, and a system to compensate inter-symbol interference (ISI) for a signal at a receiver. The apparatus comprises a first logic unit to generate decision feedback equalizer (DFE) coefficients for data samples of a data signal; a second logic unit to generate DFE coefficients for edge samples of the data signal, wherein the DFE coefficients for the edge samples of the data signal are based at least in part on the DFE coefficients for the data samples of the data signal; and a third logic unit to compensate the data and edge samples of the data signal for inter-symbol interference at the data and edge samples of the data signal, wherein the third logic unit to compensate for inter-symbol interference by using the DFE coefficients for the data and edge samples generated by the first and the second logic units respectively.

Abstract: A technique for a reconditioning equalizer filter for non-constant envelope signals is described. The input to a transmitter chain is modified by a reconditioning equalizer filter, prior to being applied to the transmitter. The reconditioning equalizer filter modifies and smoothens the amplitude of the signal. The modified and smoothened signal has its peaks reduced which results in lower Crest Factor. The input to the reconditioning equalizer filter could be a baseband, intermediate frequency (IF) or radio frequency (RF) signal. When the signal is an IF or RF signal, it needs to be down-converted to baseband before being applied to the reconditioning equalizer filter. The reconditioning equalizer filter could be performed in a digital or analog domain.

Abstract: A channel estimator is configured to determine channel estimate parameters indicative of characteristics of a wireless communication channel based on a received signal comprising a known transmitted signal and a noise signal. The channel estimator is configured to apply, to the received signal, a frequency domain representation inverse of a combination of a known signal factor as a function of frequency and a noise factor.

Abstract: A method of operation in a receive circuit is disclosed. The method comprises entering an initialization mode followed by receiving training data from a lossy signaling path. The training data originates from a transmit circuit. The received training data is sampled and minimax transmit equalizer coefficients are generated based on the sampled data. The minimax transmit equalizer coefficients are then transmitted back to the transmit circuit. The initialization mode is exited and an operating mode initiated, where transmit data precoded by the minimax transmit equalizer coefficients is received.

Abstract: Techniques for operating a diversity receiver are described. A user equipment (UE) may include (i) a first receive chain having an equalizer and a first rake receiver and (ii) a second receive chain having a second rake receiver. The UE may support (i) a first mode in which only the equalizer is used to process a received transmission and (ii) a second mode in which both rake receivers are used to process the received transmission. The UE may determine a first performance metric for the first mode (e.g., based on the performance of the equalizer) and a second performance metric for the second mode (e.g., based on the performance of both rake receivers or only the first rake receiver). The UE may select the first or second mode based on the performance metrics and may power down the second receive chain if the first mode is selected.

Abstract: Systems and methods are described for performing packet loss concealment (PLC) to mitigate the effect of one or more lost frames within a series of frames that represent a speech signal. In accordance with the exemplary systems and methods, PLC is performed by searching a codebook of speech-related parameter profiles to identify content that is being spoken and by selecting a profile associated with the identified content for use in predicting or estimating speech-related parameter information associated with one or more lost frames of a speech signal. The predicted/estimated speech-related parameter information is then used to synthesize one or more frames to replace the lost frame(s) of the speech signal.

Abstract: Low-complexity channel noise reduction method and apparatus for multi-carrier mode in wireless LANs are disclosed. The method selects an optimal frequency domain channel impulse response by using a known long training sequence and a highly protected signaling sequence of the multi-carrier mode frame structure to ensure the receiver to have a good operation threshold in different time-delay spread environments at the cost of a low complexity. Instead of detecting time domain channel responses, the method directly performs noise reduction to a noise-containing frequency domain channel by using preset Wiener filtering coefficients to obtain multiple frequency domain channel responses, among which there must be a relatively optimal frequency domain channel response. The relatively optimal frequency domain channel response can be selected by using the highly protected signaling sequence to calculate the signaling frequency domain channel.

Abstract: Low-complexity channel noise reduction method and apparatus for multi-carrier mode in wireless LANs are disclosed. The method selects an optimal frequency domain channel impulse response by using a known long training sequence and a highly protected signaling sequence of the multi-carrier mode frame structure to ensure the receiver to have a good operation threshold in different time-delay spread environments at the cost of a low complexity. Instead of detecting time domain channel responses, the method directly performs noise reduction to a noise-containing frequency domain channel by using preset Wiener filtering coefficients to obtain multiple frequency domain channel responses, among which there must be a relatively optimal frequency domain channel response. The relatively optimal frequency domain channel response can be selected by using the highly protected signaling sequence to calculate the signaling frequency domain channel.

Abstract: An apparatus including an adder, a delay line, and a first detector. The adder may be configured to generate an input signal in response to a received signal and a feedback signal. The feedback signal may include a contribution from each of a plurality of delayed versions of the input signal. The contribution from each of the plurality of delayed versions of the input signal may be determined by a respective weight value. The delay line may be configured to generate the plurality of delayed versions of the input signal. The first detector may be configured to recover a data sample from the input signal in response to a clock signal.

Abstract: A clock-synchronized method for universal serial bus (USB) is described. The method includes the following steps of: (a) a transmitter sends a periodic signal to a host unit during a first time interval; (b) the host unit transmits a first equalization training sequence signal to a receiver during a second time interval to train the receiver and the transmitter continuously sends the periodic signal to the host unit; (c) a clock and data recovery device extracts the first equalization training sequence signal during the second time interval to generate a extracted clock signal and a data signal; and (d) the transmitter sends a second equalization training sequence signal to the host unit based on the extracted clock signal during the third time interval to train the host unit and the receiver and the transmitter commonly utilize the extracted clock signal as a reference clock.

Abstract: An integrated circuit (IC), comprises a receiver on an IC substrate. The receiver is configured to receive a stressed input signal. A built in self test (BIST) circuit is provided on the IC substrate for testing the receiver. The BIST circuit comprises an encoder configured for receiving an input signal and identifying whether a first condition is present, in which two or more consecutive input data bits have the same polarity as each other. An output driver circuit provides the stressed input signal corresponding to the two or more consecutive input data bits. The stressed input signal has an amplitude that is larger when the encoder identifies that the first condition is present and smaller when the encoder identifies that two or more consecutive input data bits have different polarity from each other.

Abstract: A transmitter generates and transmits a low rate signal to its intended receiver. Upon receiving the low rate signal, the intended receiver generates and transmits a channel sounding response (CSR), said CSR being a short burst having a predefined transmit format and carrying predetermined information. The transmitter then analyzes the CSR and determines uplink channel response, estimates downlink channel response, and determines appropriate transmit parameter settings based on the analysis and downlink response estimate. Adjustment of the transmit parameters can be made in either the MAC or PHY layer or in a combination of both. After adjusting its transmit parameters and modulating sub-carriers with user-data according to the determined transmit settings, the transmitter transmits the user-data to the receiver on a preferred portion of bandwidth.

Abstract: Embodiments of the invention comprise a continuous-time equalizer for reducing ISI in data received from a communication channel, and methods and circuitry for tuning or calibrating that equalizer. Selected coefficients for a transfer function of the equalizer circuit are fixed, while other coefficients are tuned by an adaptive algorithm. The adaptive algorithm minimizes errors associated with the tunable coefficients based on one or more training signals sent by the transmitter and received by the equalizer circuit at the receiver. The training signals allow for a variety of error terms to be calculated, from which the tunable coefficients are updated so as to iteratively minimize the error terms and simultaneously tune the equalizer to more accurately compensate for the degrading effects of the channel.

Abstract: A method of processing broadcast data in a transmitting system includes randomizing enhanced data; Reed-Solomon (RS) encoding and Cyclic Redundancy Check encoding the randomized enhanced data to build an RS frame; encoding the enhanced data in the built RS frame at a coding rate of at least ½ or ¼; first interleaving the encoded enhanced data; deinterleaving the first interleaved enhanced data; first multiplexing enhanced data packets including the deinterleaved enhanced data with main data packets including main data; randomizing the main data in the multiplexed enhanced and main data packets; second interleaving the enhanced data in the multiplexed enhanced and main data packets and the randomized main data to output a data group having the interleaved enhanced data and the interleaved main data; trellis encoding data in the data group in a trellis encoding unit; and second multiplexing the trellis-encoded data with field synchronization data and segment synchronization data.

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 for identifying minor echoes present in an input signal in the situation where a set of major echoes has already been identified from the input signal. The method includes: computing a spectrum F corresponding to a sum of the major echoes; computing a weighted power spectrum SM of the spectrum F; subtracting the weighted power spectrum SM from a weighted power spectrum PIN of the input signal to obtain a difference spectrum; performing a stabilized division of the difference spectrum by a conjugate of the spectrum F to obtain an intermediate spectrum; computing an inverse transform of the intermediate spectrum to obtain a time-domain signal; and estimating parameters one or more of the minor echoes from the time-domain signal. The echo parameters are usable to remove at least a portion of the one or more estimated minor echoes from the input signal.

Abstract: Decision feedback equalization (DFE) circuitry and method for equalizing data signals over a wide range of data rates. By using delayed and controlled versions of the recovered data clock to retime the equalized data signal for feedback via the DFE taps, correct feedback signal timing is maintained and jitter tolerance is increased at high data rates.

Abstract: A digital communication system which applies channel coding and QAM modulation, where in QAM, at the transmitter, a number Q of bits is mapped to one QAM symbol, which is transmitted over the channel, at the receiver side, for each QAM symbol, a de-mapping is performed in order to obtain an L-value for each bit which corresponds to the QAM symbol, such that these L-values provide not only an estimation of the transmitted bits but also give information about their reliability.

Abstract: MMSE equalization in the frequency domain is emulated by applying intermediate weights on a per-frequency-bin basis and re-scaling each bin output to recover proper MMSE scaling. Time-domain samples of a received signal are transformed into a frequency-domain representation of the received signal. A frequency-domain representation of a channel response for the radio channel is calculated, and a frequency-domain representation of impairments to the desired signal is generated, the frequency-domain representation of the impairments comprising an impairment covariance matrix for each of the frequency bins. A scaling factor for each of frequency bins is calculated, based on a bin-specific signal-quality estimate for each bin, and an equalized frequency-domain sample for each of the frequency bins is computed, as a function of the scaling factors, the frequency-domain representation of the channel response, and the generated frequency-domain representation of impairments.

Abstract: Efficient decoding in IEEE 802.11ah networks can be achieved by transmitting the signal (SIG) preamble field without interleaving bits within the SIG field. This may allow channel equalization and decoding steps to be performed contemporaneously upon reception of the frame, which allows for the implementation of non-linear channel equalization techniques (e.g., maximum likelihood (ML) equalization, etc.

Abstract: An apparatus and a method for improving performance of an equalizer in a wireless communication system are provided. The apparatus of a reception end includes a search unit and an estimator. The search unit determines power values of respective taps inside a window based on a signal received via a pilot channel, and classifies the taps into one or more meaningful taps and one or more noise taps. The estimator allocates one or more 1-tap channel estimators to the one or more meaningful taps, and determines a channel estimation vector based on a channel estimation value of the one or more meaningful taps determined by the one or more 1-tap channel estimators.

Abstract: An equalizer-based receiver and an operating method thereof in a wireless communication system are provided. The equalizer-based receiver includes a reception multi-path detector, a controller, and an equalize receiver. The reception multi-path detector groups reception signals according to a predetermined reference to classify the reception signals into a plurality of delay clusters, and estimates a position of the plurality of delay clusters. The controller determines whether the plurality of delay clusters exist within a predetermined threshold range based on a result of the estimated position, and controls an operation mode of the equalizer-based receiver depending on a result of the determination. The equalize receiver performs one of a mode for removing an interference between the plurality of delay clusters and a mode for applying a diversity technique to a delay cluster under control of the controller.