Abstract: A method is used to determine information about a communication channel using an adaptive filter coupled to the channel. The adaptive filter includes adaptive filter coefficients. The filter coefficients are compared to filter coefficient thresholds. A determination is made whether one of a communication link and a channel fault exists. If a channel fault exists, a determination is made whether, i) a cable open condition exists in the channel, and ii) a cable short condition exists in the channel. An indication is made whether the channel is one of linked, open, and shorted.

Abstract: A diversity receiver system applying diversity to improve reception of coded data in presence of fading of the broadcast signal. The communication system includes a diversity receiver system receiving the coded data modulated broadcast signal from a transmission channel. The diversity receiver system has a signal acquisition device for evaluation of the signal characteristics of copies of the coded data modulated broadcast signal, extracting the coded data, control signals, and locking signals from the copies of the coded data. A diversity circuit selects one of the copies of the coded data modulated broadcast signals. An error evaluation circuit evaluates the coded data signal for errors and provides an error signal to the diversity circuit indicating an error state of the selected data, wherein the diversity circuit selects a second copy of the coded data modulated broadcast signal.

Abstract: Techniques to derive a channel estimate using substantially fewer number of complex multiplications than with a brute-force method to derive the same channel estimate. In one method, an intermediate vector B is initially derived based on K sub-vectors of a vector {circumflex over (H)} for a channel frequency response estimate and at least two DFT sub-matrices for a DFT matrix {tilde over (W)}, where K>1. An intermediate matrix A for the DFT matrix {tilde over (W)} is also obtained. A least square channel impulse response estimate is then derived based on the intermediate vector B and the intermediate matrix A. In one implementation, the intermediate vector B is obtained by first computing DFTs of a matrix ?T×L, which is formed based on the vector {circumflex over (H)}, to provide a matrix GL×L. Inner products between the columns of a base DFT sub-matrix W1 and the rows of the matrix GL×L are then computed to obtain the entries of the intermediate vector B.

Abstract: To achieve improved jitter performance within prescribed bandwidth constraints, a receiver (140) samples a digital signal (11) upon each of n periodic sample clock pulses that occur during the interval t, where n is chosen such that log2(n+1) is an integer (x) greater than zero. At the each of each interval t, the receiver generates a x+1-bit sample value having a first bit indicating the value of the digital signal being sampled, and x remaining bits which collectively indicate a sample interval during which the digital signal changed states if such a change did occur When a change does occur, the receiver inverts the first bit of each sample value upon decoding to coincide with the change in the digital signal.

Abstract: In one aspect, the present invention is directed to a technique of, and system for enhancing the performance of high-speed digital communications through a communications channel, for example a backplane. In this aspect of the present invention, a transmitter includes equalization circuitry to compensate for bandwidth limitations and reflections in high-speed digital communication systems. In one embodiment, the equalization circuitry is designed, programmed and/or configured to introduce intersymbol interference in order to improve the signal integrity in high-speed communications and enhance the operation and performance of such systems. In this regard, the equalization circuitry includes temporally overlapping leading and/or trailing taps (relative to the data (symbol) signal) to reduce, minimize, mitigate or effectively eliminate pre-cursor and/or post-cursor intersymbol interference due to, for example, bandwidth limitations and reflections in high-speed digital communication systems.

Abstract: Described is a transmission system for transmitting a multicarrier signal from a transmitter (10) to a receiver (20). The multicarrier signal comprises a plurality of subcarriers. The receiver (20) comprises a channel estimator (28) for estimating amplitudes of the subcarriers and for estimating time derivatives of the amplitudes. The receiver (20) further comprises an equalizer (24) for canceling intercarrier interference included in the received multicarrier signal in dependence on the estimated amplitudes and derivatives (29). The channel estimator (28) comprises a reduced complexity filter for deriving vectors of the estimated amplitudes and derivatives (29) from vectors of received symbols (23) and vectors of estimated symbols (27). The reduced complexity filter may be arranged for exploiting an amplitude correlation between the amplitudes of different subcarriers and/or for exploiting a derivative correlation between the derivatives of different subcarriers.

Abstract: The invention relates to a method for reducing effects of self-created digital radio frequency interference on broadband reception. In the method a DVB-T (Digital Video Broadcasting—Terrestrial) signal is received at a broadband receiver (200). The received signal is demodulated in a demodulation process. Information (210) on frequencies of self-created digital radio frequency interference is provided for the broadband reception. The information has been generated based on prior measurements and stored to a memory prior to the receiving of the DVB-T signal. The information is used in the broadband reception so as to reduce the effects of the self-created digital radio frequency interference on the broadband reception.

Abstract: A system and method for providing full-duplex data communications between an electric power distribution station and a power consumer via the power distribution line providing electric power is provided. A first information transmitter, coupled to the power distribution circuit, provides first information signals concurrently with the power signal to the power consumer via the power distribution line. A first information receiver, coupled to a power consumer device powered by the electrical power signal, receives the first information signals via the electric power distribution line. A second information transmitter coupled to the power consumer device provides second information signals concurrently with the electrical power signal. A second information receiver, coupled to the power distribution circuit, receives the second information signals via the electric power distribution line.

Abstract: A variable-length encoding apparatus capable of encoding two data groups in parallel, and a method and computer program for the same. A first encoding unit and a second encoding unit execute variable-length encoding in parallel. In order to concatenate first variable-length encoding data output from the first encoding unit and second variable-length encoding data output from the second encoding unit, the second variable-length encoding data is shifted by the number of bits of the first variable-length encoding data.

Abstract: Disclosed is a method for using a different symbol timing for users so as to reduce a multiple access interference component in a multi-carrier code division multiple access (MC-CDMA) system. For this purpose, the presented invention involves dividing the users of the MC-CDMA system into two groups and applying an offset to the symbol timing between the user groups to cause a symbol transition of the opposite user group in the middle of the symbol interval, thereby reducing the multiple access interference component included in a symbol decision variable after a chip combination.

Abstract: An apparatus and method to synchronize devices in a network to a sub-millisecond timing accuracy. In a first embodiment, the transmission of data is synchronized between a first source device and destination devices communicatively coupled to a network. In a second embodiment, data is deterministically transmitted between a first source device and destination devices communicatively coupled to a network. In a third embodiment, a deterministic network synchronizes the transmission of data between a first source device and destination devices coupled to a network.

Abstract: A wander generator has a random number signal generator unit, a filter unit, a clock generator unit, a modulator unit, and a setting unit. The random number generator unit sequentially generates random number signals comprised of a plurality of bits at a constant speed in accordance with a predetermined algorithm. The filter unit receives a random number signal sequence generated by the random number signal generator unit for filtering. The clock generator unit generates a clock signal. The modulator unit modulates the frequency of clock signal generated by the clock generator unit with a signal output from the filter unit. The setting unit applies the filter unit with a signal for setting each amplitude value of a spectrum of a signal sequence output from the filter unit.

Abstract: A method of receiving data, in accordance with an embodiment of the present invention, includes the acts of generating a data sampling clock signal and comparing a received clock signal to the data sampling clock signal. The data sampling clock signal is used to sample a data signal into sampled data representing a first zone, a second zone, and a third zone of the data signal. It is then determined which zone of the sampled data has a transition of the data signal and indicating a direction of change for the data sampling clock signal if the first zone or the third zone has the transition.

Abstract: Systems compensate for the presence of digital impairments using adaptive constellation techniques. Sample magnitudes are estimated from received samples transmitted during a training period using an algorithm based on minimizing the sum of squares of the estimated errors, afterwhich a suitable constellation is derived. In one embodiment, an optimum least-squares algorithm is employed. In an alternate embodiment, a least mean squares (LMS) or normalized LMS algorithm is performed.

Abstract: A method in a wireless communications device, for example, 3rd Generation (3G) Universal Mobile Telephone System (UMTS) user equipment, including estimating (210) noise power of a signal, estimating signal power (220) of the signal, estimating a signal to noise ratio (230) based on the estimated noise power and the estimated signal power, and at least partially unbiasing (240) the estimated signal to noise ratio based on the interval over which the noise power is averaged.

Abstract: A phase error correction technique in receivers such as WLAN receivers is provided. Such receivers comprise a phase error correction unit connected to receive an input signal having a phase error and adapted to generate an output signal having a corrected phase error. Further, the receiver comprises a despreader which is adapted to despread a data signal. The despreader is connected to the phase error correction unit to provide the despread data signal to the phase error correction unit. The phase error correction unit is arranged for correcting the phase error dependent on the despread data signal. The despreader may be a Barker matched filter or a CCK matched filter, and there may be provided a multiplexer for selecting one of the filters.

Abstract: A circuit arrangement to recover clock and data from a received signal comprises an electronic commutator for sampling the received signal in such a way that several sampling values of a bit cell transmitted with the received signal are distributed time-wise one after the other onto several output connections of the commutator device and emitted there in the form of corresponding intermediate signals. A first circuit combines a first group of intermediate signals of the commutator device into a first uniting signal, which serves as the basis for data recovery or comprises the recovered data signal, while a second circuit combines a second group of intermediate signals of the commutator device into a second uniting signal, which serves as the basis for clock recovery. The second uniting signal is fed to a phase regulator arrangement, which, dependent on this, sets the sampling phases assigned to the individual output connections of the commutator device.

Abstract: Systems and methods for precisely controlling the amount of redundancy introduced by a turbo encoding process. Bits having predetermined values are introduced into the turbo encoding input stream and then deleted from the turbo encoding output stream. At the receiver end, the bits having predetermined values are reintroduced into the encoded information stream as having been received with a maximum confidence level. Coding rate may be varied by varying the number of bits having predetermined values which are inserted at the encoder input. This scheme permits the amount of redundancy to be varied according to system requirements.

Abstract: This invention relates to a method and system for fast retrieval of the sequence components from phase, frequency and amplitude varying signals and synchronization therewith, and the concept of a system on a chip for power signal processing. More specifically, it relates to a method and system where the sequence components of a three-phase power signal are extracted and filtered in real time using a multirate phase-locked loop and a dual infinite impulse response filter with fault detection and reinitialization.

Abstract: A substantially passive implementation of a clock recovery circuit may be employed to reduce or eliminate the amount of jitter added to the recovered clock by the recovery circuitry. NRZ data may be received in differential form (i.e., a separate NRZ signal and an inverted NRZ signal are received). The inverted NRZ data may be delayed by one-half of a unit interval with respect to the NRZ data by a delay element. The NRZ data and the delayed NRZ data may be combined by a broadband combiner (e.g., a resistive adder). The combined signal may be split into two signals. The two split signals may be rectified by suitable components. One of the limited split signals may be subtracted from the other limited split signal to generate an output signal. The generated output signal then possesses a spectral component at a clock frequency of the NRZ data.