Abstract: In some embodiments, a method includes receiving, at a first device via a channel of a communication medium, multiple data transmissions, wherein a code rate of multiple code rates is associated with each data transmission of the multiple data transmissions. The method includes determining, based on signal characteristics of the multiple data transmissions, the data transmission from among the multiple data transmissions having a preferred physical data rate. The method also includes setting a code rate for the channel for communication from a second device to the first device via the communication medium, to the code rate of the data transmission having the preferred physical data rate.

Abstract: In some embodiments, a method includes receiving, at a receiver of a first device via a channel of a communication medium, multiple data transmissions. Each data transmission of the multiple data transmissions has a guard interval of multiple guard intervals, wherein the multiple guard intervals have different lengths. The method includes determining, based on signal characteristics of the multiple data transmissions, the data transmission from among the multiple data transmissions having a preferred physical data rate. The method includes setting a length of an adjusted guard interval for the channel for data communication from a transmitter of a second device to the receiver of the first device via the communication medium, to a length of the guard interval for the data transmission having the preferred physical data rate.

Abstract: A delay between a first signal and a second signal is estimated. The first signal and second signals are received and for each of a plurality of candidate delays between the signals, a correlation value is determined. Based on the correlation values, one of the candidate delays is selected to be used as an estimate of the delay between the first and second signals.

Abstract: Systems and methods are provided for determining a successive interference cancellation (SIC) decoding ordering in a multiple input multiple output transmission (MIMO) system with retransmissions. A plurality of codewords is transmitted in a current transmission time. Some of the codewords may have been previously transmitted in previous transmission attempts according to a retransmission protocol. The plurality of codewords is received and an ordering metric is computed for a received codeword based on channels associated with multiple transmission attempts of the codeword. A decoding ordering of the codewords is determined based on the computed ordering metric. Performance parameters such as Packet Error Rate (PER), channel gain, and/or equalizer-output Signal-to-Interference and Noise Ratio (SINR) may be used to evaluate a channel quality for each one of the transmission attempts of the codeword. The ordering metric may be updated recursively with each transmission attempt.

Abstract: Systems and methods for decreasing the amount of information sent on a feedback channel are disclosed. Spectral binning and/or a Markov state model may be used to reduce the amount of information sent on the feedback channel.

Abstract: The present invention relates to methods and apparatuses for sensing noise sources in a wireline communications environment such as a customer premises environment in a DSL system. In embodiments, the invention includes an additional sensor that is connected to power mains in a DSL customer premises environment either to characterize, at their source, noises coupling into the DSL lines, and/or to mitigate their impact into the DSL lines. One objective is associated with diagnostics that help to better characterize the noise signals themselves and derive correlation of signals sensed from the power mains and their possible projection onto the DSL line. Another objective makes use of these power line sensor signals to mitigate or to eliminate power line noises that make their way onto the DSL line. Example embodiments further include and exploit signals from additional secondary sensors such as secondary common mode, differential mode and phantom mode sensors.

Abstract: A clock generator generates a clock signal used for sampling a received signal by a comparator which compares the received signal to a reference. A phase shifter adjusts the phase of the first clock signal and a controller adjusts the phase of the clock signal to maximize the vertical eye opening of the signal at the sampling time. In an example embodiment, the phase of the clock signal is adjusted in a first direction and a measure of vertical eye opening of the signal is compared to a previous measure. If the measure of vertical eye opening has increased the signal another phase adjustment is made in the same direction and if the vertical eye opening of the signal has decreased a further phase adjustment in the opposite direction is made. By increasing the vertical eye opening of the signal the signal-to-noise ratio of the received signal is improved.

Abstract: The present disclosure presents methods and apparatuses for enhanced received signal processing using signal-based channel impulse response (CIR) estimation. For example, according to an example method presented herein, a user equipment (UE) or a component therein may receive a signal corresponding to a transmitted signal sent by a network entity, wherein the transmitted signal comprises at least a data channel, estimate chip contents of the transmitted signal, based on the received signal including the data channel, to obtain estimated chip contents, and compute an estimated channel impulse response (CIR) based on at least the estimated chip contents. Based on this estimated CIR, the UE may thereafter reprogram a received signal reconstruction filter, perform interference cancellation procedures, and/or adjust one or more equalizer taps. By performing such functions, the UE may exhibit improved communication characteristics and enable a more robust user experience.

Abstract: Methods and test equipment for measuring jitter in a Pulse Amplitude Modulated (PAM) transmitter. Under one procedure, a first two-level PAM signal test pattern is used to measure clock-related jitter separated into random and deterministic components, while a second two-level PAM signal test pattern is used to measure oven-odd jitter (EOJ). Under another procedure, A four-level PAM signal test pattern is used to measure jitter-induced noise using distortion analysis. Test equipment are also disclosed for implementing various aspects of the test methods.

Abstract: An apparatus may include a processor circuit, and a dynamic filter adjustment component for execution on the processor. The dynamic filter adjustment component may identify in a wideband communications signal a set of one or more interferer frequencies for one or more respective interferer channels of a set of communications channels to be filtered, select a kernel filter comprising a low pass filter having a channel width corresponding to a channel of the one or more interferer channels, and generate a co-channel interference (CCI) filter to stop the one or more interferer channels by inverting the kernel filter. Other embodiments are described and claimed.

Abstract: Interference classification with minimal or incomplete information. Receivers in access points and in other network devices on a wireless digital network may be switched to a spectrum monitor mode in which they provide amplitude-versus-frequency information for a chosen part of the spectrum. This may be performed by performing a FFT or similar transform on the signals from the receiver. Receivers are calibrated with known interference sources in controlled environments to determine peaks, pulse frequency, bandwidth, and other identifying parameters of the interference source in best and worst case conditions. These calibrated values are used for matching interference signatures. Calibration is also performed using partial signatures collected over a short period in the order of microseconds. These partial signals may be used to detect interferers while scanning.

Abstract: The MIMO method and apparatus disclosed herein improve throughput conditions limited by multiplicative noise by reducing the gain of the data streams associated with one or more dominant signal paths between MIMO communication nodes. As used herein, multiplicative noise refers to any noise dependent on or proportional to a signal strength at a transmitting node and/or a receiving node of a wireless communication network. An additional method and apparatus are included for determining that multiplicative noise limits the throughput conditions.

Abstract: A method for identifying the modulation scheme of a software defined radio in real-time without pilot symbols between transmitters and receivers, includes providing a predetermined look-up table (LUT) in the software-defined radio wherein the LUT is prepared by pre-calculating discrete likelihood ratio test (DLRT) function values; storing the pre-calculated DLRT values in said LUT; and indexing the pre-calculated DLRT values by addresses.

Abstract: The invention describes a method for predicting the performance of the MLD receiver in MIMO channels. The method is based on the iterative principle where the performance of the MLD decoder is derived from that of an iterative receiver architecture with similar performance. The described Iterative MIMO Effective SNR (IMES) technique maps the performance of each MIMO channel realization into a set of effective SNR values for the different streams. This set of effective SNR values can then be used to provide link adaptation feedback to the transmitter so that the most suitable transmission format can be selected according to the characteristics of the propagation channel. Alternatively, this information can be used to adapt the receiver processing to the channel conditions, thereby making it possible, for example, to reduce the receiver power consumption in good signal conditions.

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: Systems and methods for computing a signal to interference and noise power ratio estimate based on multiple domains are provided. A signal transmitted through a fading channel from a wireless transmission source is received. First estimates of (a) signal power of the received signal and (b) noise power of the received signal are computed in a first domain separately. Second estimates of (a) the signal power of the received signal and (b) the noise power of the received signal are computed in a second domain separately. The second domain is different from the first domain. The SINR estimate is determined based on one of the first and second estimates that indicate less variation in the fading channel.

Abstract: A method for measuring the asymmetric delay of a communication path includes: sending, by a first node, a first delay measurement message to a second node whose local clock is synchronized with the first node; receiving, by the first node, a second delay measurement message sent by the second node; calculating, according to time when the first delay measurement message is sent by the first node and time when the second node receives the first measurement message, a communication path delay in a direction towards the second node; calculating, according to time when the second node sends the second delay measurement message and time when the second measurement message is received by the first node, a communication path delay in a direction leaving the second node; and obtaining a measured value of the asymmetric delay of the communication path according to the communication path delays in the two directions.

Abstract: Improving signal quality by sampling an intermediate frequency signal by an analog-to-digital converter (ADC) and determining spectral characteristic data of the output signal of the ADC, and processing the spectral characteristic data to identify blocking signals and blocking spur signals that interfere with any desired signals. An adjustment is made to the frequency of one or more oscillators to reduce the interference resulting from the blocking signals if a ratio of the desired signal level to the total interfering blocker spur level is below a threshold.

Abstract: Systems and methods for decoding block and concatenated codes are provided, including channel state information estimation such as by using optimum filter lengths based on channel selectivity and adaptive decision-directed channel estimation. These improvements enhance the performance of various communication systems and consumer electronics, including HD Radio receivers and systems.

Abstract: Embodiments of the present invention provide a method and an apparatus for analyzing crosstalk between lines, where the method includes: performing frequency spectrum notching on a specific frequency band of lines of which the number is a first number among multiple lines, collecting a first group of state performance parameters of each line of lines of which the number is a second number among the multiple lines; canceling frequency spectrum notching on the specific frequency band of the to-be-analyzed line, collecting a second group of state performance parameters of each line of the lines of which the number is the second number; and determining, according to the first and second groups of state performance parameters, crosstalk of each line of the lines of which the number is the second number into the to-be-analyzed line on the specific frequency band.

Abstract: Using DSL modems as data collectors, the modems processes the data to, for example, allow easier interpretation of the line characteristics. In particular, the modems postprocess the data including calibration, filter compensation, determination of the SNR medley from the bits and gains tables and rate conversion. The interpretation process uses the postprocessed data and determines loop characterization, interferer detection, a data reduction estimation and a data rate estimation. The outputs of these determinations least allow for the characterization of the line conditions between the two modems.

Abstract: A modem or associated computing or testing device is configured to detect the presence of one or more faults that affect DSL communications, and upon their detection, generate, for example, an indication, communication or message that recommends corrective action. In this context, a fault is generally caused by one or more unfiltered devices, impulsive noises, malfunctioning modems, or other factor that does not affect measured attenuation or measured noise, but does affect the signal-to-noise ratio (SNR) of the link. In addition to being able to generate a message guiding a user through corrective action, the system can estimate the rate impact of the detected fault.

Abstract: Various embodiments of the present invention provide systems and methods for estimating noise components in a received signal set. For example, one embodiment of the present invention provides a noise estimation circuit that includes a data detector circuit and a noise component calculation circuit. The data detector circuit receives a series of data samples and provides a detected output, and the noise component calculation circuit provides an electronics noise power output and a media noise power output each calculated based at least in part on the detected output and the series of data samples.

Abstract: A method for receiving signals over a power line network, within the power line network at least one transmitter and at least one receiver communicate via at least two channels, each of the channels having a respective feeding port of the at least one transmitter and a respective receiving port of the at least one receiver, and the receiver having at least two receiving ports. The method determines a channel characteristic of each of the channels, applies a receiving port selection criterion based on the channel characteristic, and selects an excluded receiving port among the at least two receiving ports based on the receiving port selection criterion, the excluded receiving port is not used during further communication.

Abstract: In a signal measurement device, a plurality of mixers output a signal having a frequency equal to a difference between two input frequencies, and a single local signal source feeds a common local signal input to the plurality of mixers. A difference measurement unit measures a level and a phase difference between outputs of the plurality of mixers if a common correction signal input is fed to the plurality of mixers, and a level/phase measurement unit measures the level and the phase of the output of the plurality of mixers if inputs of signal to be measured common in frequency are fed to the plurality of mixers. A difference correction unit corrects a measurement result of the level/phase measurement unit based on a measurement result of the difference measurement unit if a common input of signal to be measured is fed to the plurality of mixers.

Abstract: In the communications system of the present invention, a communications terminal determines a precoding matrix index in a pilot signal received through a specific downlink channel, examines channel quality information of the downlink channel according to the determined precoding matrix index, and transmits feedback information to a serving base station, which determines a priority factor by using the examined channel quality information, and compares the priority factor with other priority factors. The comparison is used such that a base station having a high priority suggests the use of the precoding matrix to the neighboring base station.

Abstract: A receive signal processor jointly detects a signal-of-interest with one or more other signals. The signal-to-interference-plus-noise ratio for the signal-of-interest is determined by computing per-subcarrier signal-to-interference-plus-noise ratios for a plurality of subcarriers carrying the signal-of-interest, computing per-subcarrier capacities for the subcarriers based on the per subcarrier signal to interference ratios, and computing a total signal-to-interference-plus-noise ratio for the subcarriers based on the per-subcarrier capacities of the subcarriers.

Abstract: Various aspects of a method and a system for finding a threshold for semi-orthogonal user group selection in multiuser MIMO downlink transmission are presented. Aspects of a system for semi-orthogonal user group selection may include a processor that computes an orthogonality measurement between one of a plurality of signals and at least one of a remaining portion of the plurality of signals. The processor may compare each of the orthogonality measurements to a threshold orthogonality value based on a computed probability. The processor may select a user group, based on the threshold orthogonality value, including one of the plurality of signals and one or more signals selected from the remaining portion of the plurality of signals.

Abstract: Embodiments of the present invention provide a method and an apparatus for reconstructing data. The method includes: acquiring a self-correlation function of a root raised cosine filter coefficient and a fading factor of each antenna of channel estimation; constructing an L-dimension matrix of the self-correlation function according to the antenna; processing a result of superposing the L-dimension matrix of the self-correlation function and the fading factor of each antenna to obtain an estimate value of an actual fading factor of the each antenna; and reconstructing received data according to the estimate value of the actual fading factor to obtain reconstructed data used for cancellation. In the embodiments of the present invention, a process of performing interference cancellation for data reconstruction is closer to an actual sending process and closer to an originally sent signal, thereby improving cancellation efficiency and reducing interference.

Abstract: Data indicative of a level of stability of a DSL link is received. Based on the received data, it is determined whether the data indicates a level of stability of the DSL link that is above or below and minimum threshold. If the level of stability of the DSL link is below the minimum threshold, die noise associated with the DSL link before the time of failure is compared with the noise of failure. If the difference between the noise before and after the time of failure exceeds a threshold, then the difference in noise is characterized as a stationary noise associated with the DSL link. However, if the difference between the noise before and after the time of failure is below the threshold, a determination is made whether the failure is associated with a loss of power to the DSL link or a severe impulse noise event the difference in noise is characterized accordingly.

Abstract: Embodiments of the present disclosure provide a reporting allocation unit, an indicator interpretation unit and methods of operating a reporting allocation unit and an indicator interpretation unit. In one embodiment, the reporting allocation unit includes an indicator configuration module configured to provide reporting interval and offset values of corresponding rank and channel quality indicators for user equipment. The reporting allocation unit also includes a sending module configured to transmit the reporting interval and offset values to the user equipment.

Abstract: A data processing method, an equalizer, and a receiver in a wireless communication system including a relay station are provided. The data processing method includes: receiving a base station signal from a base station; receiving a relay station signal from a relay station; determining a propagation delay between the base station signal and the relay station signal; generating an equalizing signal in which interference generated between the base station signal and the relay station signal is alleviated in consideration of the propagation delay; and recovering information bits transmitted by the base station from the equalizing signal. According to an exemplary embodiment of the present invention, it is possible to alleviate performance deterioration due to an interference problem generated in a relay system.

Abstract: Some demonstrative embodiments include devices, systems and/or methods of beam selection for beamformed communication. For example, an apparatus may include a controller to control a plurality of antenna subarrays to form a plurality of directional beams for communicating a beamformed diversity wireless transmission over a plurality of selected directional links, which are selected based on at least one predefined selection metric.

Abstract: For voltage values (observed noise sequence) in an electronic power line (communication medium) which are obtained at a predetermined interval, initial values of noise characteristics based on a statistic of the observed noise sequence itself are decided by a moment method (S301 to S307), the noise characteristics (state transition probabilities and state noise power) for maximization of the likelihood of the observed noise sequence are obtained from the initial values by MAP (Maximum A Posteriori) estimation using a Baum-Welch algorithm (S309 to S312), a state sequence is estimated from the obtained noise characteristics, and an impulsive noise at each time point is detected.

Abstract: Methods and systems to mitigate impulse interference in an OFDM QAM signal. A per-symbol noise measure, or quality measure (QM) is computed for a symbol k as a MSE of distances between carriers in the symbol and points of corresponding QAM constellations. MSE(k) is averaged over multiple symbols to compute a background signal QM, AVG_MSE(k). If MSE(k) exceeds AVG_MSE(k) by a moderate amount, symbol k may be moderately affected by impulse interference, and per-carrier SNR estimates are downgraded for all data carriers in symbol k, prior to LLR computation. SNR downgrading may be linear or step-wise based on an extent to which MSE(k) exceeds AVG_MSE(k). If MSE(k) exceeds AVG_MSE(k) by a significant amount, symbol k may be significantly affected by impulse interference, and LLRs may be set to indicate that all data carriers are erased in symbol k.

Abstract: A test system for testing wireless circuitry in an electronic device is provided. The test system may include a test host and a tester. The tester may provide radio-frequency test signals to a device under test (DUT). The DUT may include radio-frequency decoding circuitry that processes the test signals using a communications protocol and digital demodulator circuitry that processes the test signals without using the communications protocol. The digital demodulator circuitry may include transformation circuitry that performs fast Fourier transforms on the test signals to create frequency-domain performance data. The test host may compute a noise floor and signal-to-noise ratio based on the frequency-domain performance data. The test host may compare the computed noise floor and signal-to-noise ratio to predetermined thresholds to characterize the radio-frequency performance of the wireless circuitry.

Abstract: A channel estimating method and device are provided. The method includes: performing multi-path searching on a pilot channel, and performing interpolation on a channel estimation value at a radial position of the multi-path searching (101); performing raised cosine de-convolution on the channel estimation value that undergoes the interpolation (102); acquiring the channel estimation value at each radial position in the pilot channel according to the channel estimation value that undergoes the raised cosine de-convolution and a sample deviation acquired by performing the multi-path searching (103). The channel estimating method and device eliminate the sample deviation of the channel estimation value, improve the demodulation performance, and evidently reduce the operation workload.

Abstract: A method for determining a corrected estimated variance representative of the condition of reception of signals representative of symbols transferred by an emitter to a receiver through a communication channel. The method includes, executed by the receiver, producing an estimation of the variance by a Wiener channel estimator comprising a linear filter of which coefficients are determined at least from a given average signal to interference plus noise ratio value. The method further includes, executed by the receiver, multiplying the estimation of the variance by a correction factor. The value of the correction factor, being dependent at least on the number of coefficients of the linear filter of the Wiener channel estimator.

Abstract: An evaluation device is configured to provide a transceiver system with performance information thereof. The transceiver system models a channel between a transmitter and a receiver thereof using Nakagami distribution with a fading parameter. The evaluation device includes a setting module operable to set an average signal-to-noise rate (SNR) for the channel between the transmitter and the receiver, a computing module operable to estimate a symbol error rate related to a signal received by the receiver from the transmitter based upon the fading parameter and the average SNR, and an output module operable to provide the average SNR and the symbol error rate as the performance information of the transceiver system.

Abstract: A signal generating device has a display, central processing unit and a waveform generating circuit. The central processing unit generates a user interface on the display for setting parameters for a serial data pattern and a parameter for an intersymbol interference and a bandwidth extension pre-emphasis effect on the serial data pattern. A waveform record file is generated using the serial data pattern parameters and the intersymbol interference effect and bandwidth extension pre-emphasis effect parameter. A waveform generation circuit receives the waveform record file and generates a serial data pattern analog output signal having the intersymbol interference effect or the bandwidth extension pre-emphasis effects defined by the intersymbol interference and bandwidth extension pre-emphasis effect parameter.

Abstract: A signal-to-interference estimate is generated using unknown data symbols in place of or in addition to pilot symbols. Data received over a data channel (traffic channel or control channel) are collected. The data symbols are then used to compute an observation metric based on deviations of the data symbols from a predetermined set of possible data symbols, wherein one of the data symbols and symbol constellation is normalized. A data channel signal-to-interference ratio is then computed based on the observation metric.

Abstract: The present invention relates to data processing techniques in multi-channel data transmission systems. In this invention, a novel approach is proposed to deal with FEXT interferences in the application of high/ultra-high speed Ethernet systems. Compared with the traditional FEXT cancellation approaches, the proposed FEXT canceller can deal with the non-causal part of FEXT, and thus can achieve better cancellation performance. Instead of using the conventional DFE, structure, TH precoding technique is incorporated into the proposed design to alleviate the error propagation problem. The resulting FEXT cancellers do not contain feedback loops which makes the high speed VLSI implementation easy. A modified design is also developed by using a finite signal as the input to the FEXT canceller such that the hardware complexity of the proposed FEXT canceller can be reduced.

Abstract: Devices and methods for determining transmission rates based on a virtual diversity receiver (VDR) scheme are disclosed. Performance is improved through determination of appropriate transmission rates, which are determined based on one or more signal to interference plus noise ratios (SINRs). The SINRs are calculated using virtual noise and channel coefficient values obtained as part of the VDR scheme. Utilizing an underlying pilot structure a user device may receive several sets of symbols. These symbols are then used to obtain both real and virtual channel noise power values and channel coefficients. These values and coefficients are then used to determine first and second SINR values indicative of one or more channels in the communication network. These SINR values may correlate to transmission rates (modulation order and/or coding rate). The SINRs may be sent to a base station, or the user device itself may determine one or more transmission rates.

Abstract: A modem or associated computing or testing device is configured to detect the presence of one or more faults that affect DSL communications, and upon their detection, generate, for example, an indication, communication or message that recommends corrective action. In this context, a fault is generally caused by one or more unfiltered devices, impulsive noises, malfunctioning modems, or other factor that does not affect measured attenuation or measured noise, but does affect the signal-to-noise ratio (SNR) of the link. In addition to being able to generate a message guiding a user through corrective action, the system can estimate the rate impact of the detected fault.

Abstract: Channel emulation in a PC computing platform including at least one general purpose parallel processor (GPPP) includes defining a plurality of fading channels in a GPPP and generating complex tap coefficients in a GPPP for the fading channels.

Abstract: Described herein are various methods for a communication device (e.g., a mobile station) receiving an AQPSK modulated signal (e.g., a VAMOS signal) to estimate a subchannel power imbalance ratio (SCPIR). Advantageously, the methods are not computationally complex and do not suffer from poor numerical performance.

Abstract: Techniques are generally described related to modeling a wireless communication system that includes multiple communication connections. Example systems, apparatuses, methods and processes may include one or more of identifying a first parameter and a first operational characteristic of interest of a first one of the communication connections, activating the first one of the communication connections based on the first parameter, collecting data associated with the first parameter and the first operational characteristic of interest when the first one of the communication connections is active; applying a statistical technique to the collected data to establish a model, and validating the model.

Abstract: The embodiments described herein provide a method and system for determining the extent to which a plurality of media signals are out of sync with each other.

Abstract: A method includes receiving reference signals in a mobile communication terminal, which is designed to receive data-carrying signals that are transmitted from a base station using one of multiple predefined Modulation and Coding Schemes (MCSs). One or more pre-calculated mappings between Signal-to-Noise Ratio (SNR) and error rate for one or more of the MCSs are held in the communication terminal. The pre-calculated mappings are adjusted according to one or more transmission parameters of the data-carrying signals. Measures indicative of respective actual spectral efficiencies that are achievable by the MCSs are estimated based on the adjusted mappings using the received reference signals. A preferred MCS is selected based on the estimated measures, and feedback that is indicative of the preferred MCS is sent to the base station.

Abstract: The invention describes a method for predicting the performance of the MLD receiver in MIMO channels. The method is based on the iterative principle where the performance of the MLD decoder is derived from that of an iterative receiver architecture with similar performance. The described Iterative MIMO Effective SNR (IMES) technique maps the performance of each MIMO channel realization into a set of effective SNR values for the different streams. This set of effective SNR values can then be used to provide link adaptation feedback to the transmitter so that the most suitable transmission format can be selected according to the characteristics of the propagation channel. Alternatively, this information can be used to adapt the receiver processing to the channel conditions, thereby making it possible, for example, to reduce the receiver power consumption in good signal conditions.