Abstract: A system implementing a distributed communication system consisting of assignable common equipment using centrally located processors for performing data network services, bidirectional route-able communications link from common equipment to distributed equipment, and distributed equipment located near subscribers. Data network services are combination of wireline for use on a wired connection to a subscriber and wireless for use on radio connection to a subscriber. Data network services include protocol and modulation processing for the relevant wired or wireless communications standard. The distributed equipment used to send and receive signals to plurality of subscribers. The distributed equipment may support both wireline and wireless subscribers or may have separate subsystems for each.

Abstract: A parallelized or array method is developed for the generation of Reed Solomon parity bytes which utilizes multiple digital logic operations or computer instructions implemented using digital logic. At least one of the operations or instructions used performs the following combinations of steps: a) provide an operand representing N feedback terms where N is greater than one, b) computation of N by M Galios Field polynomial multiplications where M is greater than one, and c) computation of (N?1) by M Galios Field additions producing M result bytes. In this case the result bytes are used to modify the Reed Solomon parity bytes in either a separate operation or instruction or as part of the same operation. A parallelized or array method is also developed for the generation of Reed Solomon syndrome bytes which utilizes multiple digital logic operations or computer instructions implemented using digital logic.

Abstract: A method of applying a multidimensional error reduction/correction algorithm on a stream of one dimensional symbols, by converting the stream of one dimensional symbols into a corresponding stream of two dimensional symbols; and, applying the multidimensional error reduction/correction algorithm to the stream of two dimensional symbols. The invention also provides a method of normalizing a metric used by an error reduction/correction algorithm on a stream of symbols wherein the symbols are non-uniformly spaced, by: determining a minimum distance (dmin) between two closest symbols in the stream, for each symbol in the stream, determining a minimum distance (dsym) between each symbol in the stream and each of its adjacent neighboring symbols, and, normalizing the metric used by the error reduction/correction algorithm by the ratio dmin/dsym.

Abstract: This application illustrates several techniques to incorporate AES hardware logic into a processor such that the AES operations are accessed as instructions of the processor. Once the AES operations are initiated by a processor instruction, they operate independently of the processor allowing the processor to perform other operations. In these implementations, the processor may perform other operations to save preceding data already processed by the AES operations. Also, the processor may perform other operations to prepare data for a subsequent AES operation. The AES hardware may have registers to buffer data results from a preceding AES operation so that the processor may read such data results after the AES hardware has initiated another operation. The AES hardware may also have registers to buffer data prepared for a subsequent AES operation so that the processor may prepare data for the following AES operation while the AES hardware is still completing a current operation.

Abstract: A novel vector processor architecture, and hardware and processing features associated therewith, provide both vector processing and superscalar processing features.

Abstract: Methods of determining systemic impairments in a telecommunications network comprise sending a candidate set of digital symbols from a digital modem to an analog modem. The symbols are affected by systemic impairments in the network. Data information symbols or mapping tables are derived in the analog modem. The data information symbols or mapping tables are then provided to the digital modem. The digital modem may use the data information symbols or mapping tables in a variety of manners, such as for data transmission, spectral shaping, echo cancellation, or adaptation to robbed bit signaling.

Abstract: A method of discovering characteristics of a PCM channel between a first PCM modem and a second PCM modem, comprising the steps of creating a PCM representation of a probing tone ensemble, where the probing tone ensemble comprises one or more tones, transmitting the PCM representation of the probing tone ensemble from the first PCM modem to the second PCM modem, receiving the PCM representation of the probing tone ensemble by the second PCM modem; and, processing the PCM representation of the probing tone ensemble to determine characteristics of the PCM channel.

Abstract: A method of asymmetrical forward error correction for a communication link having two communication directions, comprising a first type of forward error correction method in a first direction of the communication link and a second type of forward error correction method in a second direction of the communication link, where the first and second types of forward error correction methods are different.

Abstract: A method of determining digital channel attenuation; comprising the steps of: receiving a known training sequence of PCM codes, which PCM codes are subjected to the attenuation within the digital channel; quantizing the received known training sequence of PCM codes according to a predetermined thresholding procedure; identifying identical PCM codes created as a result of the thresholding procedure; and, determining the attenuation of the digital channel based upon the identification of identical PCM codes. A method is also disclosed for determining a digital channel PCM code transformation comprising receiving a known training sequence of PCM codes, which PCM codes are subjected to the PCM code transformation within the digital channel, quantizing the received known training sequence of PCM codes according to a predetermined thresholding procedure, and determining the transformation of transmitted codes to those received.

Abstract: A method of applying a multidimensional error reduction/correction algorithm on a stream of one dimensional symbols, comprising converting the stream of one dimensional symbols into a corresponding stream of two dimensional symbols; and, applying the multidimensional error reduction/correction algorithm to the stream of two dimensional symbols. The invention also provides a method of normalizing a metric used by an error reduction/correction algorithm on a stream of symbols wherein the symbols are non-uniformly spaced, comprising: determining a minimum distance (dmin) between two closest symbols in the stream, for each symbol in the stream, determining a minimum distance (dsym) between each symbol in the stream and each of its adjacent neighboring symbols, and, normalizing the metric used by the error reduction/correction algorithm by the ratio dmin/dsym.

Abstract: The encoder of a communication device is configurable such that the encoder may operate in any of a variety of forward error correction modes. Further, for each mode, a variety of encoding parameters may be configured. The configurability of forward error correction modes and/or parameters enables communication devices to perform interactive configuration processes, whereby a communicating device specifies the type of forward error correction that the other is to perform. This configuration may be bidirectional, such that each device selects the forward error correction provided by the other. Each device may further configure its decoder to decode the forward error correction mode that it has selected for the other communication device. In other embodiments two communicating devices may implement two different modes of forward error correction.

Abstract: A non-separable symbol constellation may comprise constituent constellations having separable I and Q. Such a non-separable constellation may be decoded with the efficiency of a separable constellation by decoding for each of the constituent constellations individually. In a transmitter, transmit data may be mapped to symbols by selecting a constituent constellation and I and Q values for a symbol to be transmitted. In a receiver, decoders may decode for each constituent individually.

Abstract: A transmitter produces a modulated signal with forward error correction from an information bit stream in a QAM transmitter. The transmitter produces parity bit streams that correspond to an inputted information bit stream using first and second concatenated coders interconnected by an interleaver. Subsets of the first and second parity bit streams are selected in accordance with a puncturing pattern. A variety of novel puncturing patterns providing various coding rates for various constellations are disclosed. The transmitter combines the selected subsets of said first and second parity bit streams with said information bit stream. A QAM symbol stream is produced by mapping a first subset of the combined bit streams to an I dimension and mapping a second subset of the combined bit streams to a Q dimension. The QAM symbol stream is modulated to produce a modulated signal that is transmitted over a communication link. A complementary receiver is also disclosed.

Abstract: In a receiver, an outer decoder in an inner/outer decoder scheme receives bit error information or bit error probability information from an inner decoder rather than being generated internally by the outer decoder. The inner decoder may be a soft-decision decoder that provides bit error probabilities, or a sum-product decoder that provides bit error information. Thus, unlike conventional outer decoders, the outer decoder does not require a conventional first stage for determining errors in the output bit stream of the inner decoder based on the bits of the output bit stream themselves. A related transmitter uses a sum-product inner decoder in conjunction with an outer decoder.

Abstract: A method of compensating for systemic impairments in a telecommunications network is disclosed. The method may involve transmitting a candidate set of digital symbols from a digital model to an analog modem, processing an analog representation of said candidate set of digital symbols in the analog modem, deriving a set of data information symbols from the analog representation of the candidate set of digital symbols, transmitting a representation of the data information symbols from the said analog modem to the digital modem, and using the representation of the data information symbols in digital modem for subsequent transmission of data from the digital modem.

Abstract: A method of shaping a transmit spectrum of a PCM modem comprising: selecting a first symbol from a first subset of predetermined symbols; converting said first symbol to its linear value equivalent representation; applying said linear value to a transmit shaping transfer function to obtain a shaping function result; and using said shaping function result to choose a second subset of predetermined symbols for transmission of a second symbol. A method of shaping a transmit spectrum of a PCM modem, comprising: converting a symbol to its linear value equivalent representation; and, applying said linear value to a transmit shaping transfer function to obtain a shaping cost function result, wherein said transmit shaping transfer is expressed in the form of H(z)=(1−a1z−1)/(1−b1z−1) wherein: a1 and b1 are coefficients selected to represent the desired spectral shape.

Abstract: A method of mapping a substring of a bit stream to a symbol selected from a set of symbols, comprising: determining if the numeric value of an n bit substring of the bit stream is below a threshold; selecting the symbol from a first subset of symbols if the numeric value is below the threshold; selecting the symbol from a second subset if the numeric value is equal to or greater than the threshold and the next bit of the bit stream is a 0; and, selecting the symbol from a third subset if the numeric value is equal to or greater than the threshold and the next bit of the bit stream is a 1.

Abstract: The problem of thresholding is considered from a clustering point of view and a novel weight-based clustering method (WCThresh) is implemented in a neural network image processor 50. The neural network image processor 50 uses weights 51-53, representing clusters of gray scale pixels of an image of document 43, to provide a threshold for the image of document 43. The processor 50 modifies weights 51-53 with the input pixels and comparator 60 using a nearest value criterion to provide the threshold.

Abstract: In a mail sorting system 10, output pixel intensities of an optical scanner 18 have their contrast locally enhanced. A contrast enhancer 24 uses statistical methods (averaging, standard deviation) coupled with empirical stretch and offset data stored in a ROM 25, to enhance pixel contrast in a pipelined processing operation.

Abstract: A digital data memory unit and memory unit array, each unit of which can be searched in accordance with the contents thereof and updated, utilizes a digital storage element in the form of a register, latch, or memory cell, a comparator and control logic. Data is presented to the units in parallel on data lines and compare data is supplied in parallel to the units along other data lines. Parallel search of data in each unit, with multiple updates in units where the stored data matches the compare data, occurs rapidly and in one clock cycle (e.g., approximately 50 nanoseconds). The control logic responds to a match output from the comparator and an update enable pulse to enable a new data word on the data lines to be written into the digital storage element of the unit. The memory unit array is useful in image processing for storing pixel values and searching and updating these values in the process of image analysis to recognize certain images.