Abstract: A priority assignment method and device are set forth for assigning a priority to a selected speech frame coded by a linear predictive coder based on at least two of: an energy of the speech frame, a log spectral distance between a frame and a frame immediately previous, and a pitch predictor coefficient for the selected speech frame. The invention protects against loss of perceptually important and hard-to-reconstruct speech frames.
Abstract: A method and apparatus utilizes "Lindsley's Law," a polynomial convergence algorithm, suitable even for high convergence rates, to implement more efficient reciprocal j.sup.th root, and hence, j.sup.th root itself, computations of desired inputs. The invention emphasizes multiplication, instead of addition, as the iterative operator, thereby reducing error at a rate relative to a power of a selected convergence rate.
Abstract: A heat sink-hybrid circuit assembly clamping device (100) and method (200) are provided for minimizing hybrid circuit assembly substrate-transistor solder joint stress. The clamping device is positioned and selected to provide a net coefficient of linear expansion (CLE) substantially of a magnitude equal to a net coefficient of the substrate material such that uniform pressure and contact are obtained between the transistors of hybrid circuit assemblies and the heat sink.
Abstract: The device and method provide precoding and symbol-rate transmitter spectral shaping of signals representative of digital information. The invention improves reliability of reception in the presence of non-Gaussian channel noise. The present invention also provides a flexible way of choosing between linear equalization, precoding without spectral shaping, and precoding with spectral shaping.
Abstract: A method of and apparatus for allocating memory for storage of vocabularies used in adaptive data compression of a frame-multiplexed data stream of a data communications network. More specifically, a memory of a data compression encoder of the network is partitioned into a plurality of sections for the temporary storage of a corresponding plurality of data compression vocabularies. A memory section of the plurality is assigned to a current frame of the frame-multiplexed data stream based on information of the current frame for storage of a vocabulary created adaptively from the current frame.
Type:
Grant
Filed:
April 29, 1991
Date of Patent:
September 14, 1993
Assignee:
Codex Corporation
Inventors:
Michael Gutman, Michael G. Hluchyj, James A. Pasco-Anderson
Abstract: An apparatus and method (200) for providing a hybrid circuit assembly carrier bracket are included wherein the bracket is constructed and arranged to provide controlled placement of at least a first power transistor (124, 126) and to provide a highly efficient thermal transfer and dissipating arrangement. The bracket is constructed and arranged to provide for placement of at least a first substrate for a hybrid circuit assembly thereon, and includes at least a first power transistor aperture (120, 122) with at least two bracket projections (146, 148) for permitting placement of said transistor on plural electrical contacts (104, 106). The heat generated by components on the circuit board(s) is transferred and dissipated substantially by biasing at least one bracket projection member resiliently against a heat sink (108, 110, 112, 114, 116, 118).
Abstract: A method and device are set forth for providing improved diversity reception to a receiver system in a communication system, the receiver system having at least one receiver on each of at least a first and a second receiver branch. The method and device provide, upon receipt of signals on the receiver branches, for utilizing received signal strength voltages to determine control voltage values, utilizing the control voltage values to amplify the designated signal (the designated signal being, for example, a signal having a received signal strength (RSSI) greater than a predetermined threshold) to obtain an amplified designated signal, and generating a resultant signal in view of the at least first amplified designated signal. The control voltage values are utilized to obtain at least one weighted difference. The at least one weighted difference is utilized to obtain an adjusted amplification of the at least one designated signal in accordance with a linear approximation.
Abstract: A queueing and dequeueing mechanism for use in an integrated fast packet network, wherein fast packets from differing traffic types are multiplexed with one another through use of a weighted round-robin bandwidth allocation mechanism (517). Fast packets within a particular traffic type are selected for transmission through use of a head of line priority service (514), a packet discard mechanism (516), or both. The weighted round-robin bandwidth allocation mechanism functions, in part, based upon a credit counter for each queue group that represents a particular traffic type.
Type:
Grant
Filed:
July 11, 1990
Date of Patent:
July 27, 1993
Assignee:
Codex Corporation
Inventors:
Michael G. Hluchyj, Amit Bhargave, Nanying Yin
Abstract: A multi-level digital signal data stream termination detector is set forth that utilizes detection of multiple relatively short detection patterns separated by a time less than a predetermined allowable time to detect digital data stream termination even in the presence of simulcast distortion.
Abstract: A method and system are set forth for providing dynamic RF communication resources to a mobile unit as that mobile unit changes geographic areas such that RF communication resource use by that mobile unit is generally not forcibly terminated as that mobile unit roves to a geographical area not served by the RF communication resource where the mobile unit is presently located.
Abstract: A method and device are provided for processing an input value to provide an output trigonometric function value of the input value. It comprises a method and device for modifying the input value to obtain an approximation value, determining an error value with respect to the approximation value, generating first and second function values with respect to the approximation value, the first and second function values typically being trigonometric function values and typically being obtained from a memory device, determining at least one correction value utilizing a predetermined number of terms of at least one power series, and combining the at least one correction value with the first and second function values to determine the output trigonometric function value.
Abstract: A two wire modem selects a carrier frequency in a baud rate from a predetermined plurality of carrier frequencies and baud rates to communicate with another modem over a communication media in a full duplex mode based on signal and echo characteristics of the communication media estimated by the modem. In addition, the processes of estimating channel characteristics and estimating range are combined in a common start up procedure comprising a plurality of successive time segments for a call modem to communicate with an answer modem over a communication media. Still further, a method is provided for switching from a primary communication media connection to a secondary connection of a data communications network for communication by first and second modems coupled to the network. More specifically, when a failure is detected in the primary connection, the secondary connection is qualified before switching thereto.
Type:
Grant
Filed:
April 15, 1991
Date of Patent:
May 25, 1993
Assignee:
Codex Corporation
Inventors:
Manickam R. Sridhar, Aniruddha Mukherjee, John L. Moran, III
Abstract: Apparatus for interfacing a network manager to a network of communication devices over a single communications channel of a plurality of signals is disclosed. Each communication device of the network is uniquely assigned a poll address for communication selection by the network manager which is operative to establish communication with a communication device of the network by transmitting the poll address thereof over the single communication channel. The network of communication devices are coupleable together in a daisy chain through input and output port circuits thereof to form the single communications channel. The input port circuit of each communications device receives and transmits signals from and to the single communications channel upstream of its position in the daisy chain and the output port circuit of each receives and transmits signals from and to the single communications channel downstream of its position in the daisy chain.
Type:
Grant
Filed:
January 4, 1991
Date of Patent:
May 11, 1993
Assignee:
Codex Corporation
Inventors:
Gerald A. Kammerer, Paul M. Piekarski, Robert W. Coia