Abstract: A transmitter within a line driver circuit is configured to supply data pulses over existing residential wiring. The transmitter is implemented in a CMOS integrated circuit. The transmitter comprises three stages: a front-end digital/analog convertor (DAC), an intermediate DAC, and a current amplifier. The first stage dictates whether the output signal is in high power mode or low power mode. The intermediate DAC, as the second stage, controls the waveform shape and tunes the edge rate, thereby outputting a positive current signal and a negative current signal. The final stage amplifies these current signals to yield current signals having a desired waveform shape, power mode, and edge rate.

Abstract: The present invention is directed to a method and arrangement for phase-locking to an incoming signal using a fast-acting start-up mode followed by a second steady-state mode of operation. The method includes providing a reference signal by dividing the incoming signal by m during a phase-lock initiation stage and by dividing by n thereafter, providing an output signal having a frequency that is synchronized to the incoming signal when the arrangement is phase-locked to the incoming signal, and providing a feedback signal by dividing the output signal by x during a phase-lock initiation stage and by dividing by y thereafter. A phase difference between the feedback and reference signals is detected and the frequency-controllable oscillator is controlled, so that the frequency of the output signal is synchronized to the incoming signal.

Abstract: A semiconductor process is disclosed which forms openings in a dielectric layer through which the emitter region and collector region of lateral bipolar junction transistors are formed. In one embodiment of the invention, the emitter openings for the lateral bipolar junction transistors are first protected by a photoresist layer that is patterned to expose the collector openings for the transistors. A first implant is performed through the exposed windows in the dielectric layer and into the exposed substrate or epitaxial layer therebelow, and then diffused to a suitable depth. The patterned photoresist is then removed to additionally expose the emitter openings, and a second implant is performed, this time into both the collector and the emitter regions, and then diffused to a suitable depth that is shallower than the first implant (used in the collector).

Abstract: A method and system for improved detection of analog signals, where such signals are composed of one or more analog frequencies of defined duration. In the method and system, an analog signal is received. A stream of data samples is created from the received analog signal. Based on the stream of data samples, a duration is calculated for one or more analog frequencies contained within the received analog signal. The duration is calculated for the one or more frequencies by utilizing a calculated signal energy for each of the one or more analog frequencies. The calculated signal energies for each of the one or more analog frequencies are used to determine a number of frequency-specific data samples. The number of frequency-specific data samples are then utilized with a sampling rate to calculate the duration of the each of the one or more analog frequencies.

Abstract: In one aspect of the present invention, a method and apparatus are provided for tracking a plurality of frequency-shift-key modulated signals in a communications device. The method includes determining a first threshold value for a first input signal of the plurality of signals, comparing the first input signal to the first threshold value and providing a first output signal. The method includes determining a second threshold value for a second input signal of the plurality of signals, and retaining at least a portion of the first threshold value while determining the second threshold value.

Abstract: A speech recognition system utilizes both matrix and vector quantizers as front ends to a second stage speech classifier such as hidden Markov models (HMMs) and utilizes neural network postprocessing to, for example, improve speech recognition performance. Matrix quantization exploits the “evolution” of the speech short-term spectral envelopes as well as frequency domain information, and vector quantization (VQ) primarily operates on frequency domain information. Time domain information may be substantially limited which may introduce error into the matrix quantization, and the VQ may provide error compensation. The matrix and vector quantizers may split spectral subbands to target selected frequencies for enhanced processing and may use fuzzy associations to develop fuzzy observation sequence data. A mixer provides a variety of input data to the neural network for classification determination. The neural network's ability to analyze the input data generally enhances recognition accuracy.

Abstract: A digital cordless telephone system using lossless pulse code modulation (PCM) for encoding an audio signal. By using an efficiently implemented and uncompressed encoding scheme, the system substantially reduces implementation costs and improves the quality of transmission for white signals such as modem signals. A transceiver implementation includes a PCM coder, an RF transmitter, an RF receiver, and a PCM decoder. Also presented is a method for communicating an audio signal from a transmitter unit to a remote receiver unit. The method includes steps of sampling an audio signal into a PCM data stream, modulating the PCM data stream onto a carrier, transmitting the carrier, receiving the carrier, demodulating the PCM data stream from the carrier, and generating a reconstructed audio signal from the PCM data stream.

Abstract: A novel collision detecting method at the physical layer is provided for use in a multi-point DMT communication system. A time mark transmitted at the beginning of a portion of a random access data communication is followed by an ID signal for identifying the communication station. The ID signal produced based on the time mark may be transmitted between the time mark and a data portion of the random access data communication. The time mark distorted by a communication channel is received by a receiver of the station that transmitted it. An additional ID signal representing the same ID data as the ID signal is produced based on the received time mark. The additional ID signal is compared with the ID signal received from the communication channel. A collision event is detected if the incoming ID signal does not match the additional ID signal. In response to the detection of the collision event, the transmission of the data portion is terminated.

Abstract: A communications system includes a plurality of lines, a modulator/demodulator, a processing unit, and a negotiation unit. The modulator/demodulator is coupled to the lines and adapted to communicate data over the lines using a plurality of tone sets. Each tone set is associated with a particular line. The processing unit has an amount of available processing resources for supporting the modulator/demodulator and is adapted to generate resource availability data based on the amount of available processing resources. The negotiation unit is adapted to receive the resource availability data from the processing unit and determine a subset of available tones within each tone set based on the resource availability data. The modulator/demodulator is adapted to communicate data on each line using the subset of available tones. A method for allocating the resources of a communications system includes determining an amount of available processing resources for a processing unit.

Abstract: A memory-efficient system and method for generating data blocks “on demand” for TDMA data bursts. In one embodiment of the present invention, a GSM transmitter module converts forward error correction (FEC) coded full-rate speech frames into TDMA data blocks. The transmitter module includes a memory configured to store the FEC coded frames in a current frame buffer and a previous frame buffer, an address generator configured to generate addresses of words in the current frame buffer during even clock cycles and addresses of words in the previous frame buffer during odd clock cycles. To generate the word addresses, the address generator operates on word offsets provided by a bit position generator, which also generates intra-word bit offsets. The memory provides the data words requested by the address generator to a multiplexer, which the selects a bit from each of the data words as indicated by the intra-word bit offsets from the bit position generator.

Abstract: An electronic directory and corresponding communication device is disclosed. The directory includes telecommunications numbers. The directory may further include priority information associated with each number which is used when accessing the directory to facilitate usability. The priority information may include an indication of usage of the communication device corresponding to the directory such that access to the directory is based on usage. The directory may be built up using caller identification information received with incoming calls and may searched to retrieve a desired number.

Abstract: A cordless telephone apparatus and method of use thereof with a telephone system providing a ring cadence as a series of alternating ring and silence periods over a telephone line. The cordless telephone comprises a handset that is configured and arranged to operate in a low power mode during periods of inactivity on the telephone line and, in response to receiving a least one ring message, in a normal power mode in which the battery-powered handset acknowledges receipt of the ring message. The cordless telephone further comprises a base unit is configured and arranged to respond to a ring signal received over the telephone line by sending the ring message to the battery-powered handset through the end of each ring period, and for a portion of the subsequent silent period, until the handset reverts to the normal power mode and acknowledges receipt of the ring message.

Abstract: A reset circuit that incorporates a battery monitor and watchdog timer in an integrated circuit is disclosed. A battery monitor having an output indicative of a charge state of a battery and a watchdog timer having an output indicative of an operational state of software being executed by the integrated circuit are connected to reset logic having a reset signal output, wherein the reset logic generates a reset signal on the reset signal output if either the battery monitor output or the watchdog timer output is active.

Abstract: A handset and a base station both periodically scan all channels to determine which channels are clear. The handset clear channel information is transferred to the base station and the base station clear channel information is transferred to the handset. Those channels determined to be clear channels by both the base station and handset are determined by logically combining the clear channel information from the handset and base station and generating an array of available channels. A subset of the available channels is determined and used by both the handset and the base station to initiate communications. A starting channel in the subset is randomly chosen based on a security ID exchanged between the handset and the base station. The remaining channels are selected according to how many channels are predetermined to be scanned. The base station and handset then use only those channels in the subset to communicate.

Abstract: A digital cordless telecommunications unit that serves for communications when paired with a similar unit and connected with a network is disclosed. The unit receives and transmits analog voice signals and also transmits digital baseband signals and receives digital formatted baseband signals. The unit includes a baseband chip, as well as an audio functions block and a system control functions block. The audio functions block comprises an audio front end for receiving and transmitting the analog voice signals and an adaptive differential pulse code modulator codec, connected to the audio front end. The codec converts the analog voice signals to the digital baseband signals and converts the digital formatted baseband signals to the analog voice signals for transmission.

Abstract: A monolithic integrated circuit for providing enhanced audio performance in personal computers. The monolithic circuit includes a wavetable synthesizer; a full function stereo coding and decoding circuit including analog-to-digital and digital-to-analog conversion; data compression, and mixing and muxing of analog signals; a local memory control module for interfacing with external memory; a game-MIDI port module; a system bus interface; and a control module for compatibility and circuit control functions.

Abstract: A cordless telephone provides extended operating range and battery life. In one embodiment, a time division duplex communications protocol is used when the measured signal strength or the signal quality between the handset and a corresponding base unit does not satisfy a known criteria, such as a predetermined threshold. The telephone is also configured to operate using a frequency division duplex communications protocol when the signal strength or signal quality between the handset and the base unit satisfies the known criteria. Other aspects of the invention are directed to measuring the received signal strength of the communications channel after initial communications is established, and selecting the communications protocol that is most advantageous in light of the measured signal strength and/or signal conditions.

Abstract: Described herein is a system and method of disabling D bits in a CT2 MUX signaling channel. When the bit count equals the bit location of where the D bits are typically located in the signaling channel of a CT2 MUX, circuitry of the present invention disables a D bit enable signal from being processed. The D bit enable signal would typically allow a transmitter and receiver to, respectively, send a bit as a D bit, or process a received bit as a D bit. The suffix of the CT2 MUX, consisting of D bits, is unaffected by the present invention.

Abstract: An automatic balance system for a transmit signal of a wireless local loop communication system. The automatic balance system includes a finite impulse response (FIR) filter system, the FIR filter system including at least one FIR tap for replicating at least one portion of an echo signal, the echo signal being an undesired component of the transmit signal. The system also includes a non-adaptive infinite impulse response (IIR) filter system operatively coupled to the FIR filter system, the non-adaptive IIR filter system including an IIR tap for replicating a long-tail portion of the echo signal. A first summer is operatively coupled to the FIR filter system and non-adaptive IIR filter system, the first summer combining the output replicated portions of the echo signal from the FIR filter system and the IIR filter system to generate a replicated echo signal.

Abstract: A modem which enables re-negotiation of the selected modem technology subsequent to the original negotiation which takes place at initiation of the modem connection. The invention includes means for one modem to interrupt data transfer and transmit a signal to the other modem indicating a request that a different modem technology be used. The request may be made as a result of changing line conditions, changing system demands, changing data transfer requirements, or other altered conditions under which the modems are operating. If the modem receiving the request accepts the request, both modems re-enter negotiation to select the best modem technology under the changed conditions. The modems are then re-trained to select the best bit rate within that technology under the existing line conditions. After the new modem technology and bit rate are selected, the modems resume transferring data.