Abstract: Aspects of a method and system for interference suppression in WCDMA systems may include one or more circuits that are operable to receive a plurality of multipath signals via one or more receiving antennas. A plurality of weighting factor values may be computed based on the received multipath signals. Estimated signals may be based on the weighting factor values. Residual signals may be generated based on received signals and the estimated signals. Addback signals may be generated based on the estimated signals and the residual signals. Updated estimated signals may be generated based on the addback signals and the weighting factor values. Incremental signals may be generated based on the updated estimated signals and addback signals. Updated residual signals may be generated based on the incremental signals and previous residual signals. The interference suppressed signals may be generated based on the updated residual signals and updated estimated signals.

Abstract: Method and apparatus are provided for estimating noise variance using a long-term data aided algorithm and an interference variance using a short-term data aided algorithm. Using these estimations, an interference hypothesis may be determined. Some embodiments compute the variance for a decision directed noise sample, convert the variance for the decision directed noise to a true noise variance per packet, and convert the variance for the decision directed noise to a true noise variance per symbol. The interference hypothesis may be based on the noise variance estimations per symbol and the noise variance estimation per packet. Some embodiments determine the presence of noise based on a comparison of the noise variance per packet, the noise variance per symbol, and each hypothesis and compute the long-term noise variance. Using the long-term noise variance in place of the variance for a decision directed noise sample for a subsequent determination of interference.

Abstract: Waveform data of selected bits having jitter or noise is generated wherein the waveform date represents a serial digital signal. A signal generator displays a jitter/noise setting area and a bit selection area on a display device where jitter or noise is set and the jitter or noise settings are applied to only the bit selected with the bit selection area. The bit is selected through various ways. A user may directly input a bit pattern to be selected. Box objects corresponding to the respective bits in the digital signal may be displayed and one or more of the bits can be selected by selecting one of the box objects. Frequently used bit patterns may be stored and provided using a menu-driven interface for selecting a bit pattern. An arbitrary number of consecutive bits may be designated for receiving jitter or noise and displayed.

Abstract: The present invention provides a method and apparatus reporting a channel quality indicator of a communication system, including: detecting a first measurement reflecting a first communication quality of the communication system; providing a series of thresholds and mapping functions, each mapping functions in association with a bin defined by two adjacent thresholds, so the first measurement is mapped to the channel quality indicator by the mapping function in association with the bin which matches the first measurement; and updating at least one of the thresholds according to a second measurement which reflects a second communication quality of the communication system.

Abstract: A system for measuring inter-carrier interference (ICI) in an OFDM system includes a test symbol generator coupled to a transmitter of the OFDM system to generate an N*N orthogonal matrix having N*N test symbols, and to send the test symbols in a test symbol stream via the transmitter to a receiver of the OFDM system. The N*N test symbols are arranged by the test symbol generator into an N*N orthogonal matrix before being sent to the receiver. The system also includes an ICI measuring module coupled to the receiver to detect the N*N test symbols received in the receiver and to arrange the test symbols as a receiving matrix in the same way as the orthogonal matrix in the transmitter. The ICI measuring module outputs the receiving matrix as an ICI matrix of the OFDM system, wherein an element on the kth row, lth column of the ICI matrix represents interference from the lth sub-carrier on the kth sub-carrier, wherein k?l.

Abstract: An evaluation device is adapted for providing a transceiver system with performance information thereof. The transceiver system includes a transmitter and at least one receiver, and models a channel between the transmitter and the receiver using Nakagami distribution with a fading parameter. The evaluation device includes a signal-to-noise ratio (SNR) setting module, an error rate computing module, and an output module. The SNR setting module is operable to set an average SNR for the channel between the transmitter and the receiver of the transceiver system. The error rate computing module is operable, based upon the fading parameter, the average SNR and a number of the receiver, to compute a bit error rate over the channel between the transmitter and the receiver. The output module is operable to provide the transceiver system with the average SNR and the bit error rate as the performance information of the transceiver system.

Abstract: A level of interference affecting signal components of received communication signals is estimated and used to weight the signal components. The signal components in a each of a number of groups of signal components are weighted based on respective interference estimates to thereby adjust signal components for coloured interference, which may vary significantly between different groups of signal components. Each group of signal components may include a single component or components within a relatively narrow sub-band of the communication signals, such as a coherence bandwidth of an Orthogonal Frequency Division Multiplexing (OFDM) signal.

Abstract: An embodiment of the invention provides a method for classifying a received signal. The method includes determining a covariance matrix of signal values of the received signal, and determining an eigenvalue matrix of the covariance matrix. The eigenvalue matrix includes the eigenvalues of the covariance matrix. A first function is determined from at least one eigenvalue of the eigenvalues of the covariance matrix. A second function is determined from at least one eigenvalue of the eigenvalues of the covariance matrix, wherein the second function is different from the first function. Dependent from a comparison between a value of the first function and a value of the second function, the received signal is classified into a signal comprising data or into a noise signal.

Abstract: A method for testing a radio frequency (RF) receiver may include measuring a plurality of bit error levels for the RF receiver at a given RF frequency. The method may further include applying a Huber function to the measured plurality of bit error levels to generate a bit error ratio (BER) estimate for the RF receiver. The method would also include using the BER estimate to generate a sensitivity for the RE receiver.

Abstract: The present invention provides method and apparatus for designing modulation and coding set of communication System. The method for designing modulation and coding set designs a proper set of modulation and coding schemes (MCS), based on probability distribution of the quality of received signal in the communication system, so as to optimize the whole performance of the communication system. The method comprises the steps of: acquiring the probability distribution of the quality of the received signal in the communication system; performing a calculation on the target performance of the communication system based on the acquired probability distribution of the quality of the received signal and a plurality of MCSs, to design a proper set of MCSs for the communication system, so that a region where the probability of the quality of the received signal appears more frequently are provided with more levels of the MCSs.

Abstract: An arrangement (90) for noise rise estimation in a wireless communication system comprises a power measuring means (45) for measuring received total wideband power. A means (52) for computing estimates of a noise floor measure bases its computation on a number of the measured received total wideband powers. A means (80) for calculating values of a biased noise rise measure bases its calculations on a number of received total wideband powers or an estimation derived therefrom and a respective one of the estimates of a noise floor measure. A means (91) for providing a measure representing a long term behaviour of the values of the biased noise rise measure is provided. A means (93) for obtaining a value of a present, unbiased noise rise measure, bases its function on the measure representing a long term behaviour of the values of the biased noise rise measure. A corresponding method is also disclosed.

Abstract: Embodiments of methods and apparatus for providing downlink channel parameters determination for downlink channels associated with a multiple-input-multiple-output (MIMO) system are generally described herein. Other embodiments may be described and claimed.

Abstract: A MIMO wireless communications device supports a dual polarized mode of antenna operation and a single polarized mode of antenna operation. Antenna mode selection is performed as a function of signal to noise ration information and/or rank information corresponding to a communications channel matrix. One of a communications device's processing chains is switched between first and second polarization orientation antennas, e.g., vertical and horizontally polarized antennas, as a function of the antenna mode selection. In various embodiments, the dual polarized mode is advantageously used for high SNR users, while in the low SNR regime, where the capacity is limited by received power, the single polarized antenna configuration, sometimes referred to as the spatial MIMO configuration, is used.

Abstract: Methods and apparatuses for retiming of multirate system for clock period minimization with a polynomial time without sub-optimality. In an embodiment, a normalized factor vector for the nodes of multirate graph is introduced, allowing the formulation of the multirate graph retiming constraints to a form similar to a single rate graph. In an aspect, the retiming constraints are formulated to allowed the usage of linear programming methodology instead of integer linear programming, thus significantly reducing the complexity of the solving algorithm. The present methodology also uses multirate constraints, avoiding unfolding to single rate equivalent, thus avoiding graph size increase. In a preferred embodiment, the parameters of the multirate system are normalized to the normalized factor vector, providing efficient algorithm in term of computational time and memory usage, without any sub-optimality.

Abstract: A method of wireless communication of a wireless device includes receiving a signal indicating WWAN resources that can be utilized for communicating peer discovery signals. In addition, the method includes communicating an OFDM peer discovery signal in the WWAN resources. A method of wireless communication of a base station includes transmitting a signal to a wireless device indicating WWAN resources dedicated for a silence interval that can be utilized for communicating peer discovery signals. The WWAN resources dedicated for a silence interval include a first subset of resources and a second subset of resources. The method further includes measuring noise in the first subset of resources and refraining from measuring noise in the second subset of resources.

Abstract: There is provided a method and apparatus for estimating a signal to noise ratio (SNR) in a wireless communication system. The apparatus selects a preamble signal for each of a plurality of sectors from a reception signal experienced by fast Fourier transform (FFT), outputs a correlation signal by performing a correlation between the preamble signal for each sector and a preamble reference signal, estimates power of the reception signal and noise power for each sector based on the correlation signal, selects a minimum value from among the noise powers for the sectors, outputs a net power for each sector by subtracting the minimum value from the power of the reception signal for each sector, and calculates the SNR by dividing the net power for each sector by the minimum value.

Abstract: The invention is directed towards a method and apparatus for estimating a noise variance in a receiver of a code multiplex telecommunications system with orthogonal spreading codes, wherein respective real and imaginary parts of a sum and a difference of two estimated symbols having substantially same amplitudes are determined, and then respective minimum energy components of the determined real and imaginary parts of the sum and difference are determined. The respective minimum energy components are finally combined to obtain the noise variance. Thereby, noise variance can be estimated simply based on addition and comparison operations, which reduces complexity and processing load.

Abstract: Techniques are described that provide uplink power control techniques that can support different uplink multi-input multi-output (MIMO) transmission schemes. A mobile station determines a Signal to Interference-plus-Noise Ratio based on base and offset values transmitted from a base station. The base station can transmit the base and offset values using seven bits total. The mobile station determines an uplink transmitter power level based on the Signal to Interference-plus-Noise Ratio.

Abstract: A method, arrangement, and transceiver for monitoring noise on a twisted pair cable adapted to transfer Digital Subscriber Line (DSL) signals with a given data symbol rate. A spectrum analyzer measures the power spectral density of a background or substantially pure noise signal. A switch and frequency detector determine whether the background pure noise signal includes repetitive impulse noise, and if so, a processor calculates the pulse width of the repetitive impulse noise utilizing an established relationship between the given data symbol rate and the frequency of the repetitive impulse noise given by the power spectral density measurements.

Abstract: In one embodiment, the method includes despreading the received signals by applying an unused channelization code, determining noise power based on output of the despreading, and determining a signal-to-noise ratio, SIR, based on the noise power and at least one of the received signals.

Abstract: Provided is a signal output control section that inputs to a digitizer a reference signal whose frequency changes at each prescribed measurement cycle; a data extracting section that extracts a number of pieces of data corresponding to an integer multiple of a period of the reference signal in each measurement cycle, from pieces of data of a reference digital signal output by the digitizer according to the reference signal that come after a prescribed wait interval has passed since an initiation timing of each measurement cycle; a distortion identifying section that calculates the non-linear distortion caused by the digitizer for each frequency of the reference signal, based on the data in each measurement cycle extracted by the data extracting section; and a distortion calculating section that calculates the non-linear distortion caused by the digitizer when the analog signal input to the digitizer has a frequency that differs from any of the plurality of frequencies at which the reference signal transitions

Abstract: A method for determining notching parameters for a PLC (Power Line Communication) Signal in a PLC system, where, by notching in a targeted fashion, frequency ranges are omitted in the PLC signal and the notching parameters are selected such that any interference of the PLC signal with a radio signal is largely avoided, is characterized with regards to the determination of notching parameters even during operation of the PLC system such that, at least for a section of the PLC signals, a signal-interference ratio (SIR) is formed which, depending on the SIR, assesses the signal strength of a radio signal and, based on the assessment notching parameters, are determined or adjusted. A respective PLC system is provided.

Abstract: Disclosed is a complex condition determination unit which, to solve the problem of making it possible to change a modulation scheme adapted to rapid changes in line status, is provided with; an error-pulse switching determination means which outputs, as error-pulse determination information indicating whether an accumulated value of the number of error pulses accumulated over a predetermined period is equal to or greater than a predetermined error-pulse threshold value, the error pulses indicating whether an error exists in a received signal; a CNR (carrier-wave power to signal power ratio) modulation scheme determination means which outputs, as CNR determination information, a modulation scheme determined in accordance with a predetermined CNR threshold value and CNR information indicating the CNR of the received signal; an RSL (receive signal level) modulation scheme determination means which outputs, as RSL determination information, a modulation scheme determined in accordance with a predetermined RSL thr

Abstract: A method for improving multiple-input multiple-output MIMO downlink transmissions includes obtaining a channel state information CSI report including preferred matrix index PMI for precoding, channel quality index CQI and rank index RI at a base station from user terminals through a channel feedback; applying selectively a signal-to-interference-plus-noise-ratio SINR offset to a SINR of said CSI report; applying selectively a rate matching responsive to SINR offset or the CSI report; and controlling or adjusting the SINR offset.

Abstract: Synchronization of satellite and terrestrial broadcasts in a shared frequency arrangement is use in order to facilitate simultaneous reception of the broadcasts. A delay value is adjusted based on a synchronization between a first terrestrial broadcast and a satellite broadcast, and a delay value for a second terrestrial broadcast is adjusted based on a synchronization between the second terrestrial broadcast, the first terrestrial broadcast and the satellite broadcast. The adjustment of the relative delay values provides an improved reception pattern based on receipt of a shared frequency communication from multiple sources by improving a signal quality factor within at least selected regions of the coverage areas in which the relative delay values permit synchronization.

Abstract: A system and method for low-cost performance and compliance testing of local oscillators and transmitters for wireless RF applications. A preferred embodiment comprises observing a digital signal from within an RF circuit, manipulating the signal with digital signal processing techniques, and determining if the RF circuit passes a test based upon results from the manipulating. Since the signal is clocked at a much lower frequency than an RF output of the RF circuit and the manipulation is performed digitally, testing can be performed at different stages of the production cycle and expensive test equipment can be eliminated.

Abstract: The disclosure can provide methods and systems for autocalibrating a transceiver. The method can include upconverting a bandpass input signal by mixing the bandpass input signal with a first local oscillator signal to form an initial transmitter signal. The initial transmitter signal can be looped back to a receiver and downconverted with a second local oscillator signal having a frequency that is different from the first local oscillator to form an intermediate frequency signal. At least one of a gain and a phase of the transmitter can be adjusted based on a transmitter image sideband of the intermediate frequency signal to generate a calibrated transmitter signal having minimized transmitter image sideband.

Abstract: In a method of selecting a codebook for precoding a wireless transmission signal, a characteristic of a wireless communication channel is measured, and a codebook size is selected using (i) an expected throughput for each of a plurality of different codebook sizes given the measured characteristic of the wireless communication channel, and (ii) channel overhead associated with each of the plurality of different codebook sizes. Based on matrix selection criteria, a best matrix is selected from a codebook of the selected codebook size, and an indicator of the selected matrix is transmitted.

Abstract: A method and device are provided for producing a transmission signal to be transferred over a transmission path from an input signal, for example an xDSL signal, wherein a bandwidth of the input signal is distributed onto a plurality of frequency bands in such a way that part signals are obtained corresponding to the individual frequency bands, and wherein each part signal is conducted to separate line drivers, and wherein output signals of the individual line drivers are combined to form the transmission signal to be transferred over the transmission path by combination means, which can be designed as an adder. In order to obtain the frequency band which pertains in each case from the input signal, which can be transformed into an analogue signal with a D/A converter, filter means can be used.

Abstract: A method and apparatus is disclosed herein for forward-backward SOMA techniques. In one embodiment, the apparatus is a receiver comprising: an inner decoder structure having a soft output M-algorithm (SOMA) based multiple-in multiple-out (MIMO) joint demapper that uses a SOMA-based MIMO detection process to perform joint inner demapping over each tone, where the SOMA-based MIMO joint demapper is operable to identify a best candidate among a number of candidates by searching a detection tree for each tone using a forward pass through the detection tree, where only a number of best alternatives from every level of the tree are expanded and where soft-output related information is collected and stored, and to perform a second pass, following the forward pass, during which soft-output is computed for each bit; and an outer decoder operable with the SOMA-based inner decoder to perform iterative decoding.

Abstract: Even if a receiver has a normal gain and a lowered intermodulation distortion characteristics, a fault detection is possible. A test signal transmitter sends a test signal having at least two frequencies to a radio receiver through a coupler. A digital signal processing section receives a signal which includes an IM3 component generated by the radio receiver and measures the electric power of fundamental wave components and the IM3 component. Then, the digital signal processing section calculates the gain of the radio receiver and IIP3, which is an index for intermodulation distortion characteristics, of the radio receiver 207 from the calculated electric power. A base station control section determines whether the gain and IIP3 of the radio receiver fall in predetermined ranges to determine whether the radio receiver works normally or has a fault.

Abstract: A signal to noise power ratio estimation system for multi-carrier communication includes a phase rotator, a power estimator, a channel gain calculator, an average and selection device, a combination and calculation device and a decibel (dB) transformation device. The signal to noise power ratio estimation system makes use of a transmit parameter signaling or pilot subcarriers to blindly assist in the signal to noise power ratio estimation to accordingly gain an estimated signal to noise power ratio accurately, and thus a communication system can be calibrated to a preferred condition.

Abstract: A method for noise rise estimation in a wireless communication system comprises receiving (210) of radio signals. An interference whitening (212) is performed. A useful signal power for a first user after the interference whitening is determined (214) for a plurality of time instances. Furthermore, a first user noise floor compensation factor is derived (216) based on combining weights for the first user used in the interference whitening. A probability distribution for a compensated useful signal power for the first user is estimated (218). A conditional probability distribution of a noise floor measure is computed (220). A noise rise measure for the first user is then calculated (222) based at least on the compensated useful signal power for the first user and the conditional probability distribution of a noise floor measure.

Abstract: A method, an apparatus and a communication unit for generating precoding feedback information in a multiple frequency radio transmission system are disclosed. A rank for precoding matrices, wherein the rank is constant over the multiple frequencies, is selected and a plurality of precoding matrices having the selected rank are selected. A different precoding matrix is selected for each frequency subset of the multiple frequencies.

Abstract: Systems, methods and apparatuses for reducing HARQ retransmissions using peak power management techniques are presented. In one example, a receiver may perform multi-level error correction for reducing HARQ retransmissions. The receiver may include a Peak-to-Average-Power Ratio Management Module (PAPR MM) decoder configured to perform a first level of error correction utilizing retransmissions originating at a front end of a distal transmitter. The receiver may further include a symbol demapping module connected to the PAPR MM decoder, a deinterleaver connected to the symbol demapping module, and a decoder connected to the deinterleaver and the PAPR MM decoder, where the decoder may be configured to perform a second level of error correction utilizing retransmissions originating at a back end of the distal transmitter. A transmitter for reducing HARQ retransmissions using PAPR techniques is also presented.

Abstract: A system and method are disclosed to generate and terminate clock shift modes during initialization of a synchronous circuit (e.g., a delay-locked loop or DLL). Upon initialization, the DLL is entered into a ForceSL (Force Shift Left) mode and an On1x mode (i.e., left shifting on each clock cycle). The feedback clock that tracks the phase of the reference clock (which, in turn, is derived from the system clock) is initially delayed in a coarse phase detector prior to applying it to the coarse phase detection window. Two delayed versions of the feedback clock are sampled by the reference clock to generate a pair of phase information signals, which are then used to establish an advanced phase equal (APHEQ) signal. The APHEQ signal advances onset of the PHEQ (phase equalization) phase and is used to terminate the ForceSL and On1x modes, thereby preventing wrong ForceSL exit due to clock jitter or feedback path overshooting during On1x exit.

Abstract: A method of recovering data in a line signal which is predicted to be subjected to repetitive noise impulses, the line signal comprising a series of data frames, the method comprising the steps of: predicting a group comprising one or more frames in said line signal which are expected to be corrupted by a noise signal; blanking said group of one or more frames which are predicted to be corrupted; determining the preceding and succeeding frames adjacent to said group; and including in each said group of one or more frames one or more parity blocks wherein if said noise signal deviates from its predicted timing interval or duration and corrupts the data carried in one or more of said frames adjacent to said group, the corrupted data is recovered using one or more of said parity blocks of said group of blanked frames and the other one of said adjacent frames.

Abstract: A method for determining a beamforming vector or a beamforming channel matrix in a communication system including a transmitting station and a receiving station, and a communication system are described. The transmitting and receiving stations include respective antenna groups and respective codebooks include a plurality of predefined beamforming vectors for the antenna group.

Abstract: A method of deriving an indicator of the signal quality in an in-service packet-based network at least having means to detect errors in packets and means to determine the overall amount of network traffic received. The method comprises the steps of: obtaining a value of the number of packets received having errors therein; obtaining a value of the overall amount of the network traffic received; calculating the indicator of signal quality (eBER) using the ratio of the number of packets received having errors therein to the overall amount of network traffic received.

Abstract: This disclosure relates to method, device and system for controlling power in a communication system. A plurality of power levels is measured from a received signal that includes a pulsed noise source. The received signal is correlated with a known sequence creating a correlation metric. A signal power is determined based on the correlation metric and the plurality of power levels. An uplink signal is transmitted at a transmit power that is based on the signal power.

Abstract: The present invention discloses a method and apparatus for performing noise estimation in an OFDM system.

Abstract: In a method for estimating a signal-to-noise ratio (SNR) of an orthogonal frequency division multiplexing (OFDM) wireless mobile communication system, noise is estimated from adjacent received signals of at least two adjacent subcarriers and received signals of subcarriers, noise power is calculated by calculating a mean square value of the estimated noise by summing squares of the estimated noise, a mean square value of the received signals is calculated by summing squares of the received signals, signal power is calculated by subtracting the noise power from the mean square value of the received signals, and the SNR is calculated using the signal power and the noise power. Thus, the method of the present invention having low complexity can estimate an SNR efficiently regardless of channel changes on a frequency axis when one OFDM symbol includes preamble data.

Abstract: The present invention provides a communication device that may suppress unnecessary break points. A communication device 200 includes a noise measuring unit 205 that measures noise occurring on a communication line 300; a communication controlling unit 202 that adjusts an SNR value of a transmission signal based on the noise measured in the noise measuring unit 205 and carries out a communication; a virtual noise determining unit 206 that determines the amount of virtual noise applied to some noise and stores the determined amount of noise in a memory unit 204; and a virtual noise applying unit 207 that applies the amount of noise stored in the memory unit 204 to the noise, wherein the virtual noise determining unit 206 dynamically divides a frequency band and determines the amount of noise of the divided frequency band as the amount of virtual noise.

Abstract: One feature includes a method for implementing a fixed point recursive filter that reduces or eliminates steady state error. The method comprises obtaining a first filter state value, processing the first filter state value to remove a scaling factor to obtain a second filter state value, ascertaining that the recursive filter has reached a steady state, determining a nonlinear drift parameter based on a difference between the first filter state value and the second filter state value multiplied by the scaling factor, and adjusting the second filter state value with the nonlinear drift parameter to reduce steady state error of the recursive filter. Ascertaining that the recursive filter has reached the steady state may include determining that a filter output value at time n is equal to a filter output value at time n?1.

Abstract: The present invention provides a test device and a method enabling automatic detection of an imbalance in a power level of a digital channel. The test device includes an attenuator, a tuner, a demodulator, and an evaluation unit. According to the method, a plurality of channels are attenuated at a plurality of attenuation levels, by means of the attenuator. A digital channel is selected from the plurality of channels, by means of the tuner. A modulation error ratio (MER) of the digital channel is measured at the plurality of attenuation levels, by means of the demodulator. A variation of the MER of the digital channel with attenuation level is then evaluated, by means of the evaluation unit, to detect an imbalance in a power level of the digital channel.

Abstract: The present invention discloses an effective apparatus and method to measure the received signal quality for a GFSK modulated signal with (or without) an unknown modulation index. The signal quality measurements are based on the decoded (unknown or known) bits and the trellis of the frequency discriminator output. This trellis is pre-calibrated with a reference Rx. The transmitted modulation index is also accurately estimated in this invention.

Abstract: In an example embodiment a method comprises receiving at least one data stream from at least two transmitter antennas, wherein the at least one data stream is pre-coded by a set of weighting coefficients; receiving a pilot channel from each of the at least two transmitter antennas; processing the received at least one data stream by an equalizer with a set of equalizer filter coefficients; calculating for each of the at least one data stream following: a signal power and an interference power from other stream, if there is any intererence, at least in part based on a set of post equalizer channel coefficients and the set of weighting coefficients; a noise power at least in part based on the received pilot channels and the set of weighting coefficients; and a signal to interference and noise ratio based on the corresponding calculated signal power, interference power and noise power.

Abstract: A system, method, and a computer readable medium having instructions thereupon for synchronized multi-user multi-carrier communications are provided. For example, a synchronized multi-user multi-carrier communication system includes a transmitter, a receiver communicatively coupled to the transmitter via a plurality of communication channels associated with multiple users, and a computing device, coupled to at least one of the transmitter and the receiver, comprising a memory device in communication with one or more processors. The one or more processors are configured to obtain noise samples for the plurality of communication channels, determine a coupling between carriers on the plurality of communication channels, determine a noise model for a carrier based upon the noise samples and the determined coupling, and store the noise model in the memory device.

Abstract: An apparatus comprising an artificial noise (AN) controller coupled to a digital subscriber line (DSL) transmitter and configured to adjust an AN level for a signal transmitted by the DSL transmitter, wherein the AN level is adjusted based on an actual signal to noise ratio (SNR) of the signal from the receiver to achieve a desired SNR for the signal. Also disclosed is a method comprising maintaining a data rate in a line at about a desired level by adjusting an AN level in a transmitted signal based on a SNR of a received signal.

Abstract: Methods and apparatus for signal and interference energy estimation in a communication system. In an aspect, a method includes setting a threshold value, and comparing a channel estimate to the threshold value to determine an interference estimate (Iest). The method also includes averaging the interference estimate (Iest) to determine average channel interference (Ic), and determining interference energy (I) based on the interference estimate (Iest) and the average channel interference (Ic). In another aspect, an apparatus includes threshold logic configured to set a threshold value and compare a channel estimate to the threshold value to determine an interference estimate (Iest). The apparatus includes averaging logic configured to average the interference estimate (Iest) to determine average channel interference (Ic), and summing logic configured to determine interference energy (I) based on the interference estimate (Iest) and average channel interference (Ic).