Abstract: System and methods for determining an optimized transmit spectra (spectral distributions of transmission power) for a set of communications channels that experience cross-talk among themselves and for transmitting data on the channels. The transmit spectra are preferably constructed so that largely contiguous frequency bands are allocated to each signaling direction (upstream/downstream) on each communications channel and/or to each channel in the set of channels. In one embodiment, each communications channel is restricted to a maximum time-averaged power. The method preferably includes steps of determining the channel transfer functions of the communications channel, determining interference characteristics of the channels, calculating substantially optimal transmit spectra for the communications channels, and redistributing the frequency bins so that they are contiguously grouped in each transmit spectra. The contiguous groupings allow wider frequency bands for signaling in the channel.

Abstract: A backplane bus system and related method for increasing the throughput of cPCI-specified backplane architectures. The system includes an interposer card for transforming reflective-wave switching into incident-wave switching. Establishing incident-wave switching on the bus along with careful slot pitch and impedance layout increases the rate at which the voltage amplitude observed by all receivers connected to the bus is sufficient to produce a change of state on the first signal propagation down the bus. Most existing peripherals are configured with transceivers that produce reflective-wave switching. The present system includes an interposer card to transform that switching into incident-wave switching. A preferred transceiver for doing so and that is implemented on the interposer card is a GTLP transceiver. A state machine is employed to regulate operation of the incident-wave switching transceiver. The system may be used to permit implementation of as many as 21 slots on a conventional cPCI backplane.

Abstract: A crosstalk elimination system allowing the reduced number of cables and a downsizing of transmission equipment is disclosed. A sending equipment includes a detector for detecting a possible crosstalk timing in each of the data signals by comparing phases of the clock signals to transmit it to the receiving equipment. A receiving equipment includes a read timing shifter for shifting a read timing of each of the clock signals associated with a corresponding data signal to a no-crosstalk timing determined based on the possible crosstalk timing.

Abstract: A system and method is disclosed to the elimination of cross talk between inductive loop detector units in a security system. The system includes appropriate devices for assigning different operational frequencies of each loop detector circuit to avoid cross talk. In a further aspect it provides a system and method for determining actual operational frequencies of various loop detector circuits in a security system and for changing the resonant frequencies to eliminate cross talk.

Abstract: A novel structure for reducing cross-talk effect is disclosed. The structure includes an electric board containing a ground layer and a plurality of adapting modules. Only one of the adapting modules can operates at any one time and each adapting module includes a plurality of slots and a plurality of buses. The plurality of the slots can detachably accommodate a plurality of corresponding adapting devices. The buses are electrically connected to the plurality of slots for transmitting signals and data. When the adapting module does not operate, the corresponding the buses are connected to the ground layer of the electric board. The plurality of the buses of the modules are alternately co-laid out on the electric board.

Abstract: A method and apparatus are disclosed for reducing cross-talk in an unbalanced channel with a reduced number of redundancies. A cross-talk canceller is disclosed that uses a multi-dimensional finite impulse response (FIR) filter to process a received signal. Redundancies are reduced or even removed entirely by processing the signals received on each twisted pair in a vector form, using multi-dimensional finite impulse response filters. The signals received by a transceiver on each twisted pair are represented in a vector form so that the signals received on each twisted pair, and the cross-talk effect that each signal has on one another, can be performed collectively. A multi-dimensional cross-talk canceller processes a vector representation of the corresponding signals transmitted by the transceiver on each twisted pair.

Abstract: A system for adjusting transmission power levels of transceivers in order to reduce crosstalk utilizes a transmitter and logic. The transmitter is configured to transmit signals to a customer transceiver over a first communication connection that is bound within a binder. The logic is configured to estimate a distance of a data path between the transmitter and the customer transceiver based on at least one signal communicated over the data path. The logic is further configured to adjust a transmission power level of the transmitter based on the estimated distance such that signals transmitted by the transmitter to the customer transceiver are spectrally compatible with signals transmitted from another transceiver over a second communication connection that is bound within the binder.

Abstract: Systems and techniques are disclosed relating to communications. The systems and techniques involve transmitting to a remote location a first signal at a first energy level followed by a second signal at a second energy level, determining a target transmission energy level as a function of a target quality parameter at the remote location, and computing the second energy level as a function of the target transmission energy level and the first energy level. It is emphasized that this abstract is provided solely to assist a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.

Abstract: A method of cancelling crosstalk between a primary and a secondary signals contained in a FDM signal, wherein the primary signal comprises a binary encoded signal and the secondary signal has a lower signal amplitude than the primary signal, the method comprising the steps of (a) applying 2R and/or 3R regeneration to a primary signal recovery portion of the FDM signal for obtaining an estimate of the primary signal, and (b) utilising at least a portion of the estimated primary signal to substantially remove a primary signal contribution in a secondary signal recovery portion of the FDM signal for recovering the secondary signal.

Abstract: In an electronic system having logic agents that communicate with each other through one or more signal lines, a method for testing high speed digital signaling on the signal lines is disclosed. The method involves sensing a first crosstalk signal induced by a first digital signal. The first digital signal is driven by a first logic agent into a signal line to communicate with a second agent. The second agent is coupled to receive the first digital signal from the signal line. A logic waveform that represents the digital signal is recorded and/or displayed, based upon the crosstalk signal. The technique may also be used for testing simultaneous bidirectional signaling on the same signal line.

Abstract: The invention specifies a method and an arrangement for testing and maintaining a switching center in a telecommunications network and the lines and appliances connected thereto, where control is effected using a test unit provided for this purpose which is connected to any digital subscriber line. This results in a significant increase in the scope of use for the test system, simple introduction of new test methods, performance of extensive tests with a single test unit, and fast and secure data transmission.

Abstract: Near-end crosstalk between identical discrete multi-tone modems is reduced by aligning the frames of all modems at a central office to each other, aligning the frames transmitted by subscribers' modems with the frames received by those modems, and including a cyclic prefix between the central office and the most distant subscriber to be served. By making adjacent DMT carrier frequencies be orthogonal to each other, the aforementioned modifications will reduce both Near End Cross-Talk and Leakage-Excited Cross-Talk. These benefits apply to modems at both the central office and subscriber ends of the communication path.

Abstract: A crosstalk compensation engine for reducing signal crosstalk effects within a data signal. Demultiplexed data signals corresponding to multiplexed data signals received via a signal transmission medium are processed to significantly reduce one or more signal crosstalk products related to one or more interactions among the multiplexed data signals within the signal transmission medium. Such signal crosstalk products include those resulting from dense wavelength-division mutiplexing of the data signals used to provide the multiplexed data signals, four-wave mixing among the multiplexed data signals within the signal transmission medium, and cross-phase modulation among the multiplexed data signals within the signal transmission medium.

Abstract: A method of communicating data across a channel that experiences near-end cross talk (NEXT) interference and far-end cross talk (FEXT) interference in alternate intervals. In one embodiment, the method comprises: a) determining NF, the number of bits per symbol usable in a FEXT-only mode of operation; b) determining NS, a number of bits per symbol usable in a single mode of operation; c) determining whether the FEXT-only mode or the single mode provides a higher data rate; and d) configuring a modem to transmit using the mode having a higher data rate. The FEXT-only mode may be determined to have a higher data rate when 126NF>340NS.

Abstract: A method and system for reducing forward crosstalk using time division multiplexing of the crosstalk noise. The method includes routing a plurality of signal lines along generally parallel paths and spacing one or more groups of the plurality of signal lines unequally in a neck in and a neck out configuration so that adjacent signal lines in each of the one or more groups of the plurality of signal lines extend away from each other within a predetermined distance. The method may also include terminating each of the plurality of signal lines using active termination. The method may also include establishing a single strip line stack up.

Abstract: The present invention provides a method for hardware reduction in the echo canceller and the near-end crosstalk canceller. The method applies an N (N is a positive integer) times divide frequency sampling operation onto the input data list of the echo canceller first (and the near-end crosstalk canceller). Then, it applies an N times multiply frequency sampling operation onto the output data list of the echo canceller (and the near-end crosstalk canceller) to generate a multiplied frequency data list. Afterwards, a low pass filter operation is applied to the multiplied frequency data list to generate a low pass data list to eliminate the echo signal (and the near-end crosstalk signal). The present invention reduces the number of the taps in the echo canceller and the near-end crosstalk canceller by using the digital signal process technique. Therefore, the area of the whole communication IC occupied by the echo canceller and the near-end crosstalk canceller can be reduced.

Abstract: In a transmission system which makes use of frequency translated signals, said system having a plurality of lines, a method for reducing crosstalk induced on a signal on a first line of said plurality of lines by a signal on a second line of said plurality of lines, comprising estimating a complex coupling factor for the crosstalk, which when multiplied by the signal on the second line estimates the induced crosstalk; and subtracting the estimated induced crosstalk from the signal on the first line. The invention comprises an approximation method for multiplying the complex coupling factor by the signal on the second line that operates on the signal on the second line through pre-rotation, scaling and multiplication by a complex number according to the coupling factor, said complex number being chosen from a bank of predetermined complex numbers so as to obtain the best approximation possible.

Abstract: Crosstalk can be cancelled in a composite communication signal (ym) which includes a primary signal component associated with communication data and which also includes a crosstalk signal component produced by applying a crosstalk coupling function to crosstalk data. An estimate (R, RCb(0), RCb(&Dgr;f)AVG) of a statistical characteristic of the crosstalk signal component is obtained from the composite communication signal. A cancellation signal (26, 46) is generated based on the statistical characteristic estimate, and an estimate (29) of the communication data is produced based on the composite communication signal and the cancellation signal.

Abstract: A method and apparatus are disclosed for canceling cross-talk in a frequency-division multiplexed communication system. The disclosed frequency-division multiplexed communication system employs multiple carriers having overlapping channels and provides an improved cross-talk cancellation mechanism to address the resulting interference. Bandwidth compression is achieved using n level amplitude modulation in each frequency band. An FDM receiver is also disclosed that decomposes the received broadband signal into each of its respective frequency bands and returns the signal to baseband in the analog domain. Analog requirements are relaxed by removing cross-talk from adjacent RF channels, from image bands, and minimizing the performance degradation caused by In-phase and Quadrature-phase (I/Q) phase and gain mismatches in modulators and demodulators. The disclosed transmitter or receiver (or both) can be fabricated on a single integrated circuit.

Abstract: In a modem pool system capable of mitigating alien crosstalk, a system including a first modem pool including at least two modems, at least one protected line connected to one of the modems, at least one sensor line connected to another of the modems, at least one alien crosstalk predictor operative to sample an alien signal on the at least one sensor line and provide an alien crosstalk prediction signal, and at least one alien crosstalk prediction summation element operative to receive the alien crosstalk prediction signal from the alien crosstalk predictor and subtract the alien crosstalk prediction signal from a data transmission signal on the protected line.

Abstract: The bandwidth of a first variable IF filter (5) for a neighbour channel suppression of a currently received channel, which first variable IF filter (5) is arranged in a first reception path of a broadcast receiver additionally comprising at least one second reception path is controlled by obtaining at least one first quality signal corresponding to a received broadcast signal on basis of a first filtering of the received and eventually pre-processed broadcast signal with said first variable IF filter (5) set to a predetermined bandwidth, obtaining at least one second quality signal corresponding to said received broadcast signal on basis of at least one second filtering of the received and eventually pre-processed broadcast signal with a second variable IF filter (13) arranged in said at least one second reception path with a bandwidth different to the first variable IF filter (5) bandwidth and/or with a different filter characteristic, and controlling the bandwidth of the first variable IF filter (5) on basi

Abstract: A method for receiving a plurality of communications from a respective plurality of transmitters using a common carrier frequency includes receiving a plurality of information signals on a common carrier frequency corresponding to the plurality of communications from the plurality of transmitters, and generating first and second separated signals corresponding to respective first and second ones of the information signals so that the first separated signal includes a primary component corresponding to the first information signal and so that the second separated signal includes a primary component corresponding to the second information signal. The first separated signal is demodulated to provide an estimate of a first information sequence corresponding to the first information signal, and the estimate of the first information sequence is modulated to provide a modulated estimate of the first information sequence.

Abstract: Described herein is a technique for reducing the effects of crosstalk between adjacent signal lines of a data path. The data path is formed by multiple signal lines arranged adjacent each other and traversing multiple segments. The signal lines are transposed between segments in a manner that is chosen to reduce differences in interline couplings between different pairs of the signal lines. The interline coupling of a pair of signal lines is represented as a function of coupling terms. A coupling term corresponds to each segment of a pair of signal lines, and is a function of the distance between the signal lines over that segment. Prior to transmitting a digital signal over the data path, the digital signal is encoded to reduce variations over time in a collective signal level of the digital signal.

Abstract: Methods, apparatus, techniques and computer program products for joint reduction of crosstalk in a synchronized, time division duplexed DSL systems use sequential removal of NEXT interference followed by removal of FEXT interference from a received DSL signal. Crosstalk is removed from a primary signal in a synchronized TDD DSL system having a primary channel that carries the primary signal, at least one NEXT generating channel that generates NEXT interference in the primary signal and at least one FEXT generating channel that generates FEXT interference in the primary signal. Signal data is acquired, where the signal data includes received signal data for the primary channel and at least one FEXT generating channel, transmitted signal data for at least one NEXT generating channel, and channel data comprising channel transfer function data and crosstalk coupling coefficient data for the primary channel, each NEXT generating channel and each FEXT generating channel.

Abstract: A parallel interference cancellation receiver that reduces impulse response interference using a model of the received signal similar to that used in block linear equalizers. Block linear equalizers comprise decorrelating receivers, zero-forcing receivers, minimum mean square error receivers and the like. The invention comprises an interference computation processor feedback loop for correcting the output of a direct interference canceller. The m iterative process removes interferers from the output symbols of a matched-filter. The PIC receiver uses received signal models of the various block linear equalizers that do not assume that each subchannel consists of several distinct paths. The receiver estimates the impulse response characteristic of each subchannel as a whole.

Abstract: The present invention relates in general to a method, apparatus, and article of manufacture for providing high-speed digital communications through a communications channel. In one aspect, the present invention employs crosstalk management techniques and structures that increase the system performance in channel communications.

Abstract: A channel card for communicating asymmetric digital subscriber line (ADSL) traffic over a communication line is provided. The channel card includes an asynchronous transfer mode (ATM) section that provides an interface to a cell bus of a chassis and provides ATM processing of cells. The channel card also includes a transceiver section that is coupled to the ATM section. The transceiver section includes at least one subscriber port. The transceiver section provides for modulation and demodulation of data for the at least one subscriber port. The transceiver section includes a common mode choke for reducing noise on the communication line.

Abstract: An Asymmetric Digital Subscriber Loop (ADSL) Discrete Multi-Tone system has disjoint and adjacent upstream and downstream channels. During the training phase of an ADSL connection, an ADSL DMT transmitter first determines a round trip propagation delay by transmitting a ranging signal to a far-end ADSL endpoint. During the subsequent communications phase, the ADSL transmitter synchronizes transmission of DMT symbols to a reference clock. In addition, the cyclic extensions of each DMT symbol are increased as a function of the propagation delay.

Abstract: A computer network is installed in a building such as a hotel having a plurality of rooms. The building has a preexisting electrical wiring grid to distribute electrical power to the rooms. At least one power line injector is operatively connected between a server computer and the electrical wiring grid to transfer data therebetween. The data is thus transmitted and received across the electrical wiring grid via a modulated carrier. A plurality of power line modems are respectively installed in the rooms of the building and are connected to the electrical wiring grid to selectively transmit and receive the data. In addition, a plurality of end user computers are respectively associated with the power line modems.

Abstract: A noise elimination method is characterized in that when transmitting signals in the same direction on at least two distributed constant lines, a resistance of a terminating resistor at a far-end is set so that voltages propagated to the far-end become equal between two kinds of propagation modes on coupled distributed constant lines. The two kinds of propagation modes are a common mode which propagates with respect to a ground plane and a differential mode which propagates between the coupled lines.

Abstract: In the particular one of interference canceling stages of the multi-user interference cancellor of the parallel processing type, the IEUs reproduce the symbol replica signals from the input signal of the stage, and also produce the local spread signals. The local spread signals have result information of the reproduction in only the IEUs, respectively, and have not been subjected to filtering, yet. Such local spread signals are multiplexed into the multiplexed signal, and then, is subjected to amplitude limitation, to be the amplitude limited signal. After then, the amplitude limited signal is filtered by the filter, to be input into the subtracter. The subtracter subtracts the filtered signal from the input signal of this stage, and thereby, to produce the output of this stage.

Abstract: A receiver has been provided, with a pre-whitening filter, to improve the probability of recovering a received signal in the presence of colored noise. Colored noise can be multipath or transmission signals to other receivers in the same spectral bandpass. The receiver system uses colored noise statistics to provide an optimal estimation in the despreading of the transmitted information. Auxiliary systems in the receiver cancel the pilot, or system acquisition symbols, improving even further the probability or recovering information in the despreading of transmitted signal. A method of pre-whitening a signal received in the presence of colored noise is also provided.

Abstract: The radio communication apparatus of the present invention changes the transmission timing of a mobile station of the self station with respect to the transmission timing of a mobile station of a peripheral transmission station. This makes it possible to extract a received signal from the self station even if the mobile station of the self station and the mobile station of the peripheral transmission station use identical unique words.

Abstract: A method for reducing disturbing effects of coupling between a first transmission/reception device and a second transmission/reception device that are each connected to a subscriber line. According to the method, a signal received on a reception path of the first device is delayed by a delay equal to p times the transmission period. A coupling signal relating to a transmission path of a second device and the reception path of the first device is estimated based on a signal transmitted over the transmission path of the second device, and the delayed signal is ridded of the estimated coupling signal. Additionally, a device for transmitting/receiving a signal is provided. The device includes a memory coupled to a reception path for temporarily storing p symbols, a subtraction circuit, and a coupling estimation block.

Abstract: All mutual interference occurring between TCM-ISDN and ADSL that communicate by utilizing a line having the same properties and using the same reference signal, and all mutual interference occurring between ADSLs are rejected, by delaying the TTR in the own ATU-C by S1 and approximately adjusting the TTR transmitted to the ATU-R which is a device to be communicated by S2.

Abstract: A communication integrated circuit, such as a full-duplex speakerphone circuit, includes a double-talk detector that operates in combination with an echo canceller. The echo canceller includes an adaptive filter with filter coefficients that are regularly adjusted to train to a received echo. The double-talk detector includes an ERLE detector for measuring the current ERLE of the echo canceller and a logic circuit for determining a best ERLE value over a plurality of measurements. The double-talk detector also includes a power estimator and noise estimator for determining a noise level. The noise level attained when the ERLE value is the best ERLE value is saved as a benchmark noise level. Filter coefficients of the echo canceller are updated or updating is blocked based on several considerations including a comparison of ERLE value to best ERLE value, the noise level in comparison to the benchmark noise level, whether the circuit is operating in half-duplex or full-duplex mode, and detection of a tone.

Abstract: A noise suppression circuit for a communications channel (12) comprises a noise reference extraction device (14), for example a hybrid transformer or circuit, for extracting from an input signal (S) a reference signal (NCM) corresponding to a noise component in the input signal and supplying the noise reference signal to a noise estimation unit (16) which derives therefrom a noise estimate (Yj) which is subtracted from the input signal to produce a noise-suppressed output signal (DOUT). The noise suppression circuit comprises a first analog-to-digital converter (24) for digitizing the input signal at a first sampling rate (Fs) and a second analog-to-digital converter for sampling the noise reference signal (NCM) at a second, lower sampling rate (FS/M), the ratio (M) between the two sampling rates being an integer. A decimator (40) decimates the input signal to produce a decimated signal (Dj+Nj).

Abstract: Disclosed is a zipper type Very high bit-rate Digital Subscriber Line (VDSL) system which comprises a transmitter including an inverse fast Fourier transformer for performing an inverse fast Fourier transform on input data, and a cyclic extension adder for adding a cyclic extension for each symbol to the data output from the inverse fast Fourier transformer and outputting the data to a transmission channel; and a receiver including a cyclic extension remover for removing the cyclic extension from the data received through the transmission channel, and a fast Fourier transformer for performing a fast Fourier transform on the data output from the cyclic extension remover.

Abstract: Crosstalk between subscriber loops used to transmit different broadband services through the same bundled telephone cable is a significant limitation to providing digital subscriber line services. A method for estimating the crosstalk, identifying the sources of the crosstalk and predicting additional sources of crosstalk are disclosed. The crosstalk sources are identified in the frequency domain by maximizing the correlation with a “basis set” of received crosstalk PSDs which consist of the cascade of a finite set of known transmit PSDs types times a representative set of crosstalk couplings. Multiple crosstalk types are identified with a technique of successive spectral subtraction. This information can be used to perform crosstalk cancellation and spectrum management for DSL systems.

Abstract: Modems using a telephone line for high speed communications between them are arranged to monitor crosstalk from other existing communications systems with which they may mutually interfere, and adjust the power spectral densities (PSDs) of their transmitted signals to reduce overlap between the PSDs of the different systems, thereby reducing near end crosstalk. Communications can thereby be optimized for whatever crosstalk conditions may exist. The modems can have a master-slave relationship for communicating buffered frames in a half-duplex manner using a collision avoidance protocol for computer network access. Analysis of monitored crosstalk PSD information can be performed by each modem, by the master modem, or by a separate computer on the network. A digital signal processor used in each modem for receiving signals can be configured to be used at other times for the monitoring of crosstalk.

Abstract: In a discrete multi-tone modem, a method of minimizing cross talk over a twisted pair of a twisted pair cable binder in which discrete multi-tone data transmission is utilized comprises the steps of one of jointly minimizing near end cross talk while maximizing total data rate, jointly minimizing an arbitrary function of total power while maximizing total data rate and minimizing total near end cross talk for a given data rate, selecting a function to be optimized and performing a bit and power allocation algorithm responsive to the selected function. The process may be combined with known optimization functions such as jointly minimizing an average bit error rate while maximizing the data rate. As a result, the process is considerably more flexible and adaptable to changing parameters such as environmental parameters impacting data transmission performance in the presence of cross talk.

Abstract: A system and method for determining transmission characteristics for a communications channel and for transmitting data on the communications channel. In one embodiment, the method starts by determining the channel's transfer function and determining interference characteristics for the channel. The interference characteristics preferably include transfer functions describing the channel's susceptibility to cross talk from neighboring channels. The channel transfer function and the interference characteristics are then examined and a transmit spectrum (or power spectral density function) is constructed for the channel. The transmit spectrum preferably uses orthogonal separation of upstream and downstream communications to increase channel capacity.

Abstract: A system and method for determining transmission characteristics for a communications channel and for transmitting data on the communications channel. In one embodiment, the method starts by determining the channel's transfer function and determining interference characteristics for the channel. The interference characteristics preferably include transfer functions describing the channel's susceptibility to cross talk from neighboring channels. The channel transfer function and the interference characteristics are then examined and a transmit spectrum (or power spectral density function) is constructed for the channel. The transmit spectrum preferably uses orthogonal separation of upstream and downstream communications to increase channel capacity.

Abstract: An apparatus, system, method, and computer program product for providing a flexible ringer for multiple deskset phones. A controller detects a flag message that precedes an incoming telephone call, and selects one or more frequencies based on a local expectation of a ringing telephone at the geographic location, or according to a user preference. A digital signal processor (DSP) generates a digital ringer signal based the selected frequencies. An audio code converts the digital ringer signal to an analog ringer signal and sends the analog ringer signal to multiple deskset phones using a receive cable. The analog ringer signal is amplified to drive a speaker that converts the analog ringer signal into an audible ringer sound at each deskset phone. The audible ringer sound can be customized for multiple geographic locations by modifying the selected frequencies used in the digital ringer signal.

Abstract: A system for determining FEXT and ELFEXT of generic cabling systems provides accurate measurements of these parameters by determining and removing the effect of the connectors at the respective ends of the link, thereby giving measurement values that correspond to the defined link, rather than including the crosstalk contributions of the connectors, which can be substantial.

Abstract: This invention relates to a double talk detecting method suited to be used for an echo canceler, and more particularly to a method for correctly detecting whether or not the double talk is present, even in the case where a speech transmitting level difference between a far-end talker and a near-end talker is comparatively large. What is assumed in the present invention is an echo canceler which can be employed in a telephone line network for transmitting a speech of a far-end talker sent through a digital line and a speech of a near-end talker sent through an analog line. A double talk detecting method applicable to the echo canceler here extracts predetermined analyzed parameters respectively from a first speech signal corresponding to the speech of the far-end talker sent from the echo canceler to a hybrid circuit and the speech of the near-end talker input to the echo canceler through the hybrid circuit. The analyzed parameters herein used include, for example, speech pitches, frequency components, etc.

Abstract: A system for digitizing voiceband signals at the remote terminal (20) of a Digital Subscriber Line (DSL) connection and embedding the digitized voiceband component into an active DSL data stream using a DSL modem (24). Voiceband transmissions between the remote terminal (20) and the central office call switching equipment (1) occur in the analog domain when the DSL modem (28) is OFF and in the digital domain when the DSL modem (28) is ON with the digital voiceband signals transmitted over a DSL link. Preferably, the remote terminal (20) can drive a real analog telephone (30) by providing battery feed, ring-trip detection, off-hook detection and ringing generation (60) In-house 4-wire lines pairs (21, 23) are configured between the modem, telephones and computer or home network to permit all digital transmission from the subscriber to the central office.

Abstract: A demodulator, within a receiver attached to a single antenna, that cancels co-channel interference within a time division multiple access (TDMA) communication system is disclosed. The demodulator takes as input a series of received signals comprising an information signal and a co-channel interference signal, both using the &pgr;/4-differential quadrature phase shift keying (DQPSK) modulation protocol. During a training period, in which the information signals corresponds to a known SYNC word, the demodulator estimates the fading coefficients corresponding to the information and interference signals. After the completion of the training period, the demodulator uses these estimates to generate accurate estimations for future information and interference signals corresponding to future data received signals.

Abstract: A method for controlling the power and/or frequency output of a digital data network's transmitters is described. The method controls the transmitter power and/or frequency output by using line loss information as well as the noise margin at both the central office and remote site sides of the transmission link. The transmitters are controlled to minimize the crosstalk between the interconnections on the network. Measurements are taken of the cable losses and signal-to-noise ratios present on the system and the transmitter power and/or frequency are adjusted to minimize unwanted interactions between transceiver pairs on the network.

Abstract: The present invention provides an interference controller and method for limiting in one cell the effect of interference generated by other cells of a wireless telecommunications system, each cell of the wireless telecommunications system having a central terminal and a plurality of subscriber terminals, communication between a central terminal and a subscriber terminal being arranged to occur over a wireless link, and a plurality of code division multiplexed channels being provided within a single frequency channel to enable data items pertaining to a plurality of wireless links to be transmitted simultaneously within different code division multiplexed channels of said single frequency channel.