Bell Communications Research, Inc.

The Kohl Group, Inc.

Telcordia Technologies, Inc.

Joseph William Lechleider

Stephen B Weinstein

Sanjai Narain

John Terrance Peoples

Charles Howard Woloszynski

One aspect of the present invention is a method for the wireless transmission of information from one or more antennas to one or more separate users. The method comprises processing information to produce transmission vectors that minimize simultaneous interference between separate user channels and adjusting the radiation patterns to minimize total system radiation power for users specified capacities. In another aspect, the present invention includes apparatus and methods for providing multiple users of a network with information in such a manner that only the user that the signals are intended for receives the information.

Flexible transport system including support for bilateral user access

A method for the direct estimation of configuration parameters defining the make-up of a physical system, such as cable lengths and gauges in the case of telephone subscriber loops, from boundary or end-point measurements of the physical structure, such as the impedance or return loss response of a subscriber loop, due to a probing source.

Determining the composition of physical structures from boundary measurements, including the composition of subscriber loops

Techniques whereby a transmitter/receiver pair are cooperatively arranged to buffer incoming data to both the transmitter and the receiver. The transmitter and receiver of the pair are coupled, generically, by pre-existing channel which has a known, fixed capacity. The transmitter/receiver pair exploits whatever delay is permissible, as determined by end-users of the data, for the data stream or streams that are using the channel for the purpose of accommodating periods of excessive instantaneous aggregate data transfer demands. The matched transmitter/receiver pair thereby permits (i) the transmission of a variable rate stream over a channel with capacity less than the peak rate of the stream, or (ii) the multiplexing of variable and/or fixed rate data streams.

Reducing the variability of the data rates of high-rate data streams in order to communicate such streams over a low-rate channel of fixed capacity

A method and system use voiceband transmission characteristics to estimate the viability of deploying broadband services over a subscriber loop in the public switched telephone network. The system gives network service providers the ability to predict the performance of broadband transmission channels, such as ADSL, on a subscriber loop from a central location and without reliance on outdated loop records maintained by a carrier. Based on this predicted performance a network service provider is able to efficiently determine the viability of deploying ADSL to a subscriber and, in turn, determine the viability of deploying ADSL in entire areas by creating an ADSL--ready consumer-lead list. The method comprises establishing an end to end voiceband modem connection from a logic device to a remote computer over a facility wherein the only analog elements reside in the subscriber loop. The system then uses the initial voiceband negotiation information collected by the modems to estimate the performance of the subscriber loop in the ADSL band. A list of ADSL ready subscribers may then be created for those subscribers whose estimated ADSL band performance is above a threshold level.

Method and system for estimating the ability of a subscriber loop to

A transceiving methodology and concomitant transceiving system wherein high speed, bursty channels are combined with uniform data rate services into a single, interleaved data stream. A system for communicating both a uniform data stream and a bursty data stream over a communication medium includes: (i) a transmitter for combining the uniform data stream and the bursty data stream into a single, interleaved stream, and for propagating the interleaved stream over the medium; and (ii) a receiver for processing the single interleaved stream to separate the uniform data stream and the bursty data stream.

Combined uniform rate and burst rate transmission system

A generalized noise canceler for canceling noise in a channel having noise composed of correlated noise components. The noise canceler is realized with a finite number of cascade networks, each network being composed of an inner product filter is series with another filter wherein both filters have characteristics determined from a eigenvector equations expressed in terms of the channel operator and noise operator.

Generalized noise cancellation in a communication channel

In a quaded cable, coupling between circuits (side circuit 1, side circuit 2, and phantom circuit) is compensated for at the receiving end of a transmission system. By transmitting known signals from the transmission end separately on each circuit, coupling between circuits is initially estimated by measuring the signals received at the opposite end on each of the circuits. Following startup, during data transmission the received data signals are modified in accordance with this initially determined coupling between circuits to produce estimated transmitted data signals. During data transmission the coupling between circuits is reestimated by storing (303) N data signals received on each circuit and the corresponding N estimated transmitted data signals on each circuit. The coupling between circuits is determined as a function of the covariance of these N received signals on each circuit and the covariance of these N estimated transmitted data signals on each circuit. The reestimated coupling is then used to modify (302) newly received data signals on each of the circuits. The coupling between circuits is reestimated either after a new data signal is received on each circuit, or after a plurality of data signals are received on each circuit.

Method and system for compensating for coupling between circuits of

In digital transmission, the combination of transmitted pulse shape and receiver sampling time that maximizes the magnitude of the channel output pulse sample is determined. The transmitted pulse shape is represented as a linear combination of orthonormal functions. The coefficients that multiply each of the functions are determined by measuring at the receiver and transmitting back to the transmitter the response of the channel to each independently transmitted function at an approximation to the optimal sampling time. A pulse shape is formed using the calculated coefficients and is transmitted to the receiver where the timing of its maximum is determined, which represents a next approximation to the optimal sampling time. By repeating a plurality of times the processes of transmitting the functions, measuring at the receiver and transmitting back to the transmitter the responses at the approximation to the optimal sampling time, calculating the coefficients, transmitting a pulse, and determining a next approximation to the optimal sampling time from the timing of the maximum in the received pulse, the coefficients and optimal sampling time will converge.

Method and apparatus for joint optimization of transmitted pulse shape

A communication system for coordinated downstream diversity transmission includes a central processing center for selecting adaptive transmitter parameters and adaptive receiver parameters to as to optimize an estimate of a transmitted data symbol received by a given mobile unit while constraining power output as well as accounting for interference to other mobile units within the propagation range of base units controlled by the central processing center. The adaptive transmitter and receiver parameters are determined from the solution of an eigenvalue formulation expressed in terms of the transmission path characteristics between the mobile unit and the base unit as well as transmission signal sources and mobile unit processing filters.

Tetherless access to communication networks

An impulse noise canceler includes circuitry which recognizes, locates, and cancels impulse noise when it occurs in an incoming signal. Impulse noise is characterized by a shape, an amplitude, and an arrival time, any or all of which may be unknown. In one implementation, adaptive circuitry is deployed to estimate the amplitude when it is the only unknown, and a replica of the impulse noise is generated and used to cancel the impulse noise in the incoming signal. In another implementation, both the arrival time and amplitude are estimated when they are unknowns, and a replica is again generated to cancel the original impulse noise. In yet another implementation, the shape, amplitude, and arrival time are all estimated of the impulse noise to produce the replica to cancel the original impulse noise.

Adaptive impulse noise canceler for digital subscriber lines

A communication system for coordinated transmission of signals from two data sources over a pair of transmission lines includes a central office transceiver and a remote transceiver terminating the corresponding ends of the pair of transmission lines. Each transceiver includes a transmitter with a complementary receiver. The signal amplitudes propagated on the lines are related to each other according to a prescribed relation that effects enhanced signal-to-noise ratio. The transmitter includes a set of amplification factors determined by the prescribed relation; similarly, the receiver also includes two sets of amplication factors to perform the dual to the transmitter operation. The transmitter incorporates a two-dimensional generalization to a conventional echo canceler, namely, an implementation to cancel both echo and near-end crosstalk interfering components. Also, the receiver incorporates a two-dimensional generalization to a conventional decision feedback equalizer, namely, an implementation to cancel both pre-cursor and post-cursor intersymbol interference as well as far-end crosstalk.

Growing community of inventors

Morristown, NJ, United States of America

Joseph William Lechleider