Matches 1 - 39 out of 39
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7295617 ADPCM decoder  
A shift register receives a quantization difference signal separated into a mantissa part and an exponent part and bit-develops the mantissa part. A shift arithmetic operation control circuit...
7180950 Low-noise feedback cancellation filter for enhanced common-mode rejection and noise immunity  
A circuit is connected between a module and a pair of wires. The circuit includes a first connection line, a second connection line, radio frequency termination circuitry, a first transformer, a...
7180933 Squelch circuitry for high speed high frequency operation  
A squelch circuit for operating at high speed and at high frequencies includes a squelch input unit, a low swing pre-amplifier and a sampling and decision circuit. The squelch input unit...
7003053 Digital broadcast receiver  
The invention provides a digital broadcast receiver which comprises a tuner 1 for selecting the desired broadcasting station from among a plurality of broadcasting stations, a demodulator circuit...
6914940 Device for improving voice signal in quality  
Provided is a device for improving voice signal in quality by discriminating a radio environment of a signal transmission path and detecting a click noise. The device for improving voice signal in...
6480532 Echo cancellation for an ADSL modem  
An echo cancellation functionality taps a digital transmit signal from a transmit channel for processing through an adaptive filter of an echo channel to generate an echo cancellation signal. The...
6212245 Communication apparatus  
The high-frequency component removing circuit is immediately started, and is not stopped unless the measurement value of the received electric intensity has maintained a value equal to or higher...
6208700 Apparatus for processing a signal received via an information carrier  
The invention relates to an apparatus for processing a signal received via an information carrier. The apparatus comprises a receiving unit (2) for receiving a signal from the information carrier,...
6061096 Digital-and-analog-TV-signal receivers, each with single first detector and shared high-band I-F amplification  
Radio receivers for receiving DTV signals, in accordance with the Advanced Television System Committee (ATSC) standard, or analog TV, in accordance with the National Television Systems Committee...
6049565 Method and apparatus for audio communication  
6047036 System and method for implementing a mute voice signal upon reception of a ADPCM zero nibble in wireless communications  
A system and method of muting a voice signal in a wireless communication system when an "all zeros" condition of a digitized serial voice input signal is detected. The mute signal which is...
6011806 Cellular telephone communication protocol  
A cellular telephone communication protocol enables a communication link primarily for the transmission of voice and data. At predetermined intervals or on-demand data regarding location, an event,...
5881101 Burst serial tone waveform signaling method and device for squelch/wake-up control of an HF transceiver  
A device and method for controlling HF single side band radio squelch operation in which a serial tone burst indicates the start and end of a transmission and identifies an on-going transmission....
5844938 Carrier based data operated squelch  
A method for providing improved carrier based data operated squelch (CDOS) includes routines for recovering the carrier signal and for analyzing the received signal. The received signal is sampled...
5615412 Digital squelch tail system and method for same  
A digital squelch tail system (120, 114) selectively attenuates audio output corresponding to a digital signal (156). A bit error rate estimator (210) generates bit error rates (201) for an input...
5598431 Method and apparatus for signal quality detection in a communication system  
A signal quality detector (200) determines the quality of an incoming received data signal within a communication device (100). The audio output of the communication device is muted and unmuted...
5598430 Analog/digital receiver  
An analog/digital receiver comprises a noise detecting circuit for checking whether a noise component, output from an analog signal detecting means, is not less than a specified value, and an RSSI...
5490166 Data muting method and apparatus using delay circuits for communication systems  
A receiver 700 having an audio output device 326 is disclosed. The receiver 700 receives a carrier signal modulated with data, voice, or a combination of both. The receiver 700 includes a...
5465404 Communications receiver with an adaptive squelch system  
A wireless communications receiver having an adaptive squelch system and operable in multiple states including a receiver (11) that provides a received signal when operating in a clear...
5285481 Receiver circuit with smart squelch  
A receiver circuit relies on four novel pulse width timer/integrators to filter input data signals having a frequency less than a preselected maximum and greater than a preselected minimum. The...
5263049 Method and apparatus for CMOS differential drive having a rapid turn off  
An integrated media attachment unit (MAU) operative for interfacing Digital Terminal Equipment (DTE) on a Local Area Network (LAN) using twisted pair media. The twisted pair function as either a...
5151922 Variable speaker muting based on received data  
A method and an apparatus for controlling a speaker mute time is provided to transmit an information message from a first communication device to a second communication device. In response to...
5109525 Two-way radio with voice storage  
A two-way radio includes a receiver having a squelch circuit for determining if a communication channel is available. A transmitter is provided for transmitting voice messages on the channel. When...
5063597 Muting circuit in a digital audio system  
A muting circuit in a digital audio system having a digital signal processor, a first latch, a second latch, a comparator for comparing data in the first and second latches, an address encoder, a...
5001703 Spectrally efficient TDM duplex communication system  
An improved duplex time division multiplexed (TDM) communication system is provided while conserving spectrum and efficiency. To accommodate two voice signals on one channel, the time allocated in...
4748685 Mobile radio communications system  
A vehicle mounted mobile transceiver (11) communicates via a secondary mobile unit (51) with a short range portable unit (10). The portable unit (10) can be either a cordless microphone or a...
4663765 Data muting method and apparatus for audo-digital communications systems  
An audio muting device for use in a transceiver which receives digital data preceded by a dotting pattern uses a detection/decoder for detecting the non-audible dotting pattern and a controller for...
4431991 Encoder for transmitted message deactivation code  
An encoder for transmission of a digital deactivation code at the end of a variable length message transmission. The encoder adds a deactivation code to the end of an operator's transmitted message...
4430742 Data muting method and apparatus for radio communications systems  
Data muting apparatus is described that mutes variable-length data signals communicated between a central station and mobile and portable radios in a dispatch radio communications system. The...
4423416 Decoder for transmitted message deactivation code  
A decoder for receiving a transmitted message followed by a digital deactivation code is described. To prevent unnecessary utilization of a broadcast channel, the decoder responds to a digital...
4418416 Frequency modulation transmitter for voice or data  
A portable frequency modulation transmitter (1) for voice or data is disclosed for operation at infrared frequencies. The transmitter comprises keyboard (200) or microphone (402) input capability...
4344175 Muting circuit  
A muting circuit detects data transitions during windows generated from received data, and counts the number of such transitions during the windows. A muting signal is produced in response to a...
4323730 Idle channel noise suppressor for speech encoders  
The idle channel for a speech encoder is detected by the detection, at the encoder comparator output, of zero-level traversals caused by noise transient signals appearing at the analog input of the...
4038604 Signal to noise ratio indicating circuit  
A radio receiver squelch circuit responds to an IF carrier modulated by any of AM voice, AM pulse, CW, interrupted CW, or angle modulated signals. After the IF carrier is amplitude normalized it is...
4020421 Muting circuit  
In radio communication systems transmitting voice and data, data is frequently transmitted at the beginning of the transmission, and this may then be followed by voice. The sound of the data in the...
3939431 Muting circuit for a radio receiver  
A zero crossing detector and one shot circuit connected to receive audio frequency signals from a receiver and provide a pulse each time the signal crosses a reference level, first and second one...
3927376 Speaker muting system  
The loud speaker of a receiver is muted during the reception of data signals at a given tone in the voice band by providing a first control signal in response to the reception at the receiver of...
3909727 Data signaling noise suppression system  
The suppression of speaker noise caused by data signaling in a mobile radio system is achieved by detecting the presence of a single audio tone frequency over a time period and when the presence of...
3665107 MONITORING CIRCUIT IN DATA SETS, WITH SIGNAL MUTING  
A circuit for use in a data set that permits the user to monitor acknowledgment tones or voice signals from a distant data receiving station, as well as permitting monitoring of tones representing...
Matches 1 - 39 out of 39