Analog Devices,inc.

Aware, Inc.

Other

Vladimir Friedman

Stuart D Sandberg

Michael Hennedy

Mark Russell

Raju Hormis

Leo Montreuil

Peter N Heller

Reza Alavi

Faramarz Sabouri

Bindu Gupta

Mohammad Reza Sherkat

Artemas Speziale

A method for delivering control information together with sampled data between a DSP and an RF/analog front-end in a high speed communication modem, which embeds sampled data and control information in frames to be transferred over one interface. A frame may comprise various fields, each may consist of one or more bytes or octets. The frame may have a data field for carrying the sampled data, and at least one control field for transferring the control information to update RF/analog front-end registers. The control field may include an octet containing a control address, an octet containing a control command, and an octet containing control data. The frame may also provide means of synchronization, e.g., by using a sync field to identify the frame boundary.

Method for transmitting sampled data and control information between a DSP and an RF/analog front-end

A single-instruction multiple-data processor comprises at least two multiply-accumulator units and associated coefficient memories and data memories. Coefficient memory addresses are formed from a base address and data samples stored in the data memories.

Pixel engine architecture

A micro-programmable filter (MFE) engine includes multiple programmable filter elements and a microcode controller. The filter elements can be configured, controlled, and combined in different ways to implement different types of filters. The MFE preferably supports multiple-execution instructions that allow a single instruction to perform multiple moves into accumulators for efficient data movement inside MFE.

Micro-programmable filter engine having plurality of filter elements interconnected in chain configuration wherein engine supports multiple filters from filter elements

A system and method for suppressing RFI receives a differential input signal V, and a signal Vwhich varies with the common mode component of V. Vis phase-shifted and then amplified with a programmable gain Gto produce an output V. A subtractor produces an output Vwhich varies with V&#x2212;V. Vis amplified with a programmable gain Gto produce an output V. An analog input signal processing circuit receives Vat an input which has an associated maximum dynamic range. A processor adjusts Gsuch that Vcovers the maximum dynamic range, adjusts the phase shift and Gto minimize V, and adjusts Gto increase Vsuch that it again covers the maximum dynamic range. The RFI in Vis substantially subtracted out, thereby enabling the full dynamic range of the analog input signal processing circuit to be employed in receiving V.

System and method for suppression of RFI interference

A power back-off system and method to mitigate far-end crosstalk interference between channels in a communication system through a generalization of the reference length and equalized FEXT methods, a power back-off method is provided that allows for control over the SNR of the channels by trading SNR on shorter channels against SNR on the longer channels. The generalization also provides for a power back-off method that can provide for two or more data rate service areas.

Equalized SNR power back-off

A method and system for providing adaptive filtering in a communication system. The method and system modify coefficients of a finite impulse response filter fed by a sequence of digital samples in accordance with an error signal in floating point format. The floating point error signal includes only a sign bit and an exponent term. The exponent term is added to an exponent term of an adaptation coefficient to produce a composite error signal. The adaptive filter is used as a linear adaptive equalizer and as an echo canceler.

Communication system

A method and system which combines a properly designed FEC and the periodic transmission of known symbols to obtain a desired error performance in a point-to-multipoint digital transmission system employing a DFE which induces error propagation. A transmitter unit includes a forward error correction encoder (FEC) which implements a code to information provided to an input of a data interleaver having block length N and interleaving depth D, and a data modulator which is coupled to an output of the data interleaver to receive a stream of data symbols. At least one receiver unit includes a decision feedback equalizer (DFE) which includes a feedback filter and provides an input to a data deinterleaver having block length N and interleaving depth D, and a FEC decoder which receives data from an output of the data deinterleaver. Sequences of known symbols of length at least equal to the length of the feedback filter are periodically added to the output of the data interleaver. The receiver unit uses knowledge of the sequence to pass correct data to the feedback filter. The number of data symbols between the periodic sequences is made equal to an integer multiple k of the interleaving Depth D, thus limiting error propagation to cause no more than k errors per codeward of block length N. The FEC code serves to correct the k errors per error propagation event.

Integrating decision feedback equalization and forward error correction

A forward error correction (FEC) system and method for use in a multipoint-to-point frame based synchronized transmission communication system in which data from users are sent in selected portions of data frames having coded symbols added thereto by encoders associated with each user. The number of bits per user assigned portions of data frames is established as an integer number of FEC code symbols. The interleaving depth is set equal to a multiple of the total number of code symbols sent by a user in a data frame. The encoders are synchronized such that all of the encoders start processing associated interleaving frames at the same time. In exemplary embodiments, the communication systems include DWMT and TDM communication systems.

Forward error correction arrangement (FEC) for multipoint to single

This invention relates to sinewave frequency measuring apparatus and method and more particularly such apparatus including a frequency estimator triggered by a zero crossing of a sinewave and means for producing sample signals at a constant rate; and a method which provides and uses an approximation of the sinewave through the zero crossing, as a straight line between two sampling periods. Errors are eliminated by means of a low pass filter. The method performs a fractional cycle correction by adding or substracting the interpolation results from the raw period time counts.

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Scotch Plains, NJ, United States of America

Vladimir Friedman