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7619964 High doppler channel estimation for OFD multiple antenna systems  
Fast fading in cellular systems causes time variation of the Channel Impulse Response (CIR) resulting in significant performance degradation that is reduced by adding a pulse train to the...
7545309 System and method for communicating low data rate information with a radar system  
A method is disclosed for transmitting low data rate symbols from a communications terminal to a burst radar transceiver. A plurality of bursts can be emitted from a burst radar transceiver, each...
7489915 Squelch circuit and communication apparatus used with the same  
A squelch circuit and a communication apparatus used with the same that are able to generate a squelch signal even if a squelch period is short and an operation of a squelch detecting circuit is...
7395042 Enhancing signals in a two-way radio system  
Embodiments of the present invention can be used to enhance signals in a peer-to-peer radio system, such as a two-way radio system. In one embodiment, the invention includes receiving a...
7359688 Device and method for displaying a status of a portable terminal by using a character image  
Disclosed are an apparatus and a method capable of expressing use state of a portable terminal by using a character image. The apparatus includes an emotion value memory for storing emotion...
7295631 Stereo demultiplexer  
A stereo demultiplexer is proposed which can be calculation power efficiently implemented in a DSP. Modern digital FM receivers exploit the information content in the in quadrature component of the...
7218903 Squelch detecting circuit  
The present invention provides a squelch detecting circuit capable of high-speed transfer while using a reduced number of high-speed operating operational amplifiers to reduce power consumption and...
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...
7149498 Detecting usable frequency channels by exploiting complex polyphase filter operation  
A circuit arrangement for detecting a usable frequency channel includes first and second devices for performing frequency conversion. The first and second frequency conversion devices have...
7120408 Differential signal squelch detection circuit and method  
An electrical circuit detects a “squelch,” or “out-of-band,” state of a differential signal pair having a positive (“p”) signal line and a negative (“n”) signal line. In one...
7096051 Enhancing signals in a two-way radio system  
Embodiments of the present invention can be used to enhance signals in a peer-to-peer radio system, such as a two-way radio system. In one embodiment, the invention includes receiving a...
7043223 Super-regenerative radio frequency receiver and its data receiving method  
A high sensitivity of a Super-Regenerative Radio Frequency Receiver and its method is provided in the embodiment of the present invention. By using a common-mode feedback circuit and by replacing...
6775527 Squelch circuit with adjustable reference level  
A squelch circuit with an adjustable reference level, having an input level comparator with a first, a second, a third and a fourth current input terminal, a first and a second input terminal, and...
6775526 Modulated input signal filter  
A modulated input signal is filtered to reduce noise. The state of the input signal controls the state of a switch. Depending upon its state, the switch connects one of two circuits to a gate. The...
6774700 Current-mode logic differential signal generation circuit employing squelch  
An electrical circuit generates both a differential data signal and a “squelch,” or “out-of-band,” state over a differential signal pair by employing common-mode logic (CML) technology. In...
6671504 Radio squelch techniques  
A radio carrier signal is detected ( 20 ) after being converted to digital form and is filtered ( 22 ). A noise estimator ( 24 ) generates a noise estimate signal by estimating the noise in the...
6671503 Wireless microphone system  
There is provided an improved receiver unit for wireless microphone system. The receiver unit accomplishes desirable mute control in accordance with state transmitting conditions of electric wave...
6564041 System and method providing improved FM carrier squelch system  
An improved squelch system ( 10 ) is provided in accordance with the present invention. The system includes a high-deviation subsystem ( 20 ) to detect a carrier with modulation, and a...
6553215 Weather radio control  
This system is for automatically controlling a radio receiver to provide an audible broadcast of the weather alert from weather stations. It may also be incorporated in a multi-band radio for...
6456833 Method for noise reduction in the reception of RF FM signals  
A method for noise reduction during FM reception and a receiver executing the method. A detected audiosignal is being attenuated. A field strength indicative muting control signal is derived from...
6397050 Multiband squelch method and apparatus  
A squelch circuit for a radio receiver that detects the presence of speech by utilizing a filter bank for filtering an intermediate frequency or baseband signal from the radio receiver into...
6397049 Two-way radio with improved squelch  
A two-way radio ( 1 ) that has a radio frequency receiver ( 2 ) having a modulated radio frequency signal output and a variable bandwidth filter ( 3 ) with an input coupled to the modulated radio...
6385440 Mobile communication receiver with asymmetric muting control  
A mobile communication receiver generates an audio signal from a radio signal received on a communication channel, detects conditions on the communication channel, mutes the audio signal according...
6374095 Method and apparatus for providing a squelch function on narrow band radio receivers  
Squelch circuitry for narrow band audio receivers which uses a sub-audible tone or coded signal to modulate the intermediate frequency in accordance with the presence of a desired broadcast signal...
6334060 Multi-channel or split-frequency, low frequency, telemetry circuit and method between transmitters and receivers  
A multi-channel system is provided for both wide-band and narrow band low frequency transmission/reception of digital telemetry. The multi-channel system uses coherent detection having a high...
6295444 Non-predictive tone-coded-squelch frequency determination method  
A non-predictive tone-coded-squelch (TCS) frequency determination method of scanning a plurality of radio frequency channels in a radio receiver and determining the presence of a standard...
6259904 Fast squelch circuit and method  
A technique is used by a squelch circuit (200) that generates a fast squelch. The technique involves generating a noise signal (211) from a demodulated signal (105), generating a squelch check...
6208848 Radio receiver squelch circuit with automatic adjustment of the squelch threshold  
A radio receiver for receiving audio frequency communications conveyed by a high-frequency carrier and occurring randomly over time. In addition to the tuning circuits, a director, an audio...
6192226 Carrier squelch processing system and apparatus  
Carrier squelch decisions are made by performing the steps of receiving an input signal (D), free of DC offset, having desired and undesired signal components, extracting the desired signal...
6101376 Squelch circuit and methodology for a multi-level quantizer  
An improved squelch circuit and methodology for a multi-level quantizer employing one or more amplifiers to amplify an input signal at different gains. Comparators coupled to corresponding...
6055421 Carrier squelch method and apparatus  
A radio receiver operates primarily in a first operating mode to process received signals (410). When a carrier signal detect is triggered while in the first operating mode (415, 420), the receiver...
6055416 Prevention of audible control signal transmission  
A communication system having a radio master and a radio slave for communicating a communication signal and a control signal via a common channel is constructed by a receiver to receive a...
6047170 Automatic squelch control for narrow band AM radio  
An improved squelch circuit which utilizes a phase-locked-loop (PLL) arrangement to track the carrier signal and identify when audio communication should be curtailed. The lock detect circuit of...
5970399 Radio channel squelching systems  
Detection of in-band noise in a radio communications voice channel is provided by mixing a signal having a known frequency into a radio signal containing a voice channel signal in an in-band range,...
5924022 RF repeater for TDMA mobile telephone systems  
An RF repeater for exchanging time division multiple access (TDMA) transmit and receive signals between a mobile handset and a CATV plant or other signal conduit has a signal timing detector...
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...
5809407 Receiver, an arrangement and a method for comparing two signals  
A receiver, an arrangement and a method for comparing two signals, based on testing whether a first signal exhibits at least one property during a first time interval, and consecutively testing if...
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...
5526530 Receiver with squelching responsive to input signal frequency  
In a receiver in which a squelch operation is switched on/off while comparing a reception level for an input frequency with a reference level, the reference level is set every input frequency in...
5491839 System for short range transmission of a plurality of signals simultaneously over the air using high frequency carriers  
A transmitter/receiver system for the simultaneous transmission and reception of plural audio signals over the air for a short range using carrier signals of frequencies over 900 MHz. A combined...
5491716 Weight-value controlled adaptive processor for spread spectrum receiver  
An adaptive processor for a spread spectrum receiver utilizes an adaptive Wiener filter and an adaptive limiter-canceller in tandem and in conjunction with bypass controls. The adaptive processor...
5473615 Digital supervisory audio tone detector  
A detector for determining the validity of a received code, such as a Digital Supervisory Audio Tone (DSAT) code. A received DSAT code is serially shifted into a shift register (10) which outputs...
5333153 Signal quality detection method and apparatus for optimum audio muting  
A digital communication device (10) comprises a signal quality detector (18) that determines the quality of the received signals and instantaneously mutes and unmutes the voice output (22) of the...
5327465 Method and apparatus for squelch circuit in network communication  
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...
5287549 Commuication device and method using transceiver squelch control  
An audio squelch control for transceiver stations in which all transceivers are initially in a Call mode with the squelch control turned on. While in the Call mode, the squelch control is turned...
5220685 Mute and automatic restore device for communications receivers  
The mute and automatic restore device is an apparatus for communication receivers and the like, whereby voice or code conversations or messages emanating from the monitoring speaker can be muted by...
5214790 Enhanced talkgroup scan algorithm  
An enhanced talkgroup scanning algorithm is provided. This algorithm provides an efficient scan function when a unit scan list contains a mixture of trunked talkgroups and conventional channels....
5187811 Error detection  
There is provided a mechanism for error detection comprising: detecting the symmetry of error distributions over adjacent time intervals and muting of a radiotelephone in response to detected loss...
5146610 Discontinuous transmission muting/unmuting system with link continuity  
A system for facilitating link continuity and prompt supervisory control in a communication system with discontinuous transmissions comprising varying the carrier power in a first communication...
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