Abstract: Disclosed herein is a broadcast signal transmitter. The broadcast signal transmitter according to an embodiment of the present invention includes an input formatting module configured to perform baseband formatting and to output at least one Physical Layer Pipe (PLP) data, a BICM module configured to perform error-correction processing on the PLP data, a framing and interleaving module configured to interleave the PLP data and to generate a signal frame, and a waveform generation module configured to insert a preamble into the signal frame and to generate a broadcast signal by OFDM-modulate the signal frame.

Abstract: A speech enhancement method is provided. The speech enhancement method includes: estimating a direction of a speaker by using an input signal, generating direction information indicating the estimated direction, detecting speech of a speaker based on a result of the estimating the direction, and enhancing the speech of the speaker by using the direction information based on a result of the detecting the speech.

Abstract: Logarithmic Detector Amplifiers (LDAs), multiple antennas, active antennas, and multiple active antennas and receivers are provided in a variety of configurations that are synchronized to reduce or eliminate interference so at to provide, a greater range and bandwidth between wireless routers and their clients in WLAN and WAN environments.

Abstract: A method and apparatus for deriving presence information of a mobile device at a presence node in a wireless system, the method having the steps of: analyzing a message received from the mobile device to determine a message type; and allocating a state for the mobile device depending on the message type found in the analyzing step. The apparatus is a presence node for deriving and maintaining presence information of a mobile device in a wireless system, the mobile device communicating with a network node, the presence node having: a communication system for communicating with the network node; a processor; and an application running on the processor, the application having means for analyzing a message received from the mobile device at the network node to determine a message type; and allocating a state for the mobile device depending on the message type found in the analyzing step.

Abstract: The invention provides a receiver comprising an input end, an Rx-chain with at least one regulating means and an output end. The receiver further comprises a feedback loop in the Rx-chain, the regulating means arranged for providing a higher or lower gain setting. The feedback loop comprises an AGC Multilevel threshold detector unit, AMU. The AMU comprises at least one Low Multilevel Threshold Detector, LMTD, and the LMTD comprises at least two threshold detectors, each detector having an associated low threshold level and detection interval, the length of the detection interval being shorter the lower the low threshold level is arranged to be set. The higher gain setting being arranged to be initiated through the feedback loop when the absolute level of an AGC input signal has been below at least one of the low threshold levels during the entire detection interval associated with that low threshold level.

Abstract: A signal processing system and method includes a transducer for receiving an analog signal having a random component and possibly an information component. The analog signal is converted into a digital signal having sample points. A nearest-neighbor calculation component calculates the expected average nearest neighbor distance between the sample points, the actual average distance and an error value. These values are corrected for edge effects. A first randomness assessment compares the actual average distance against the expected average distance with the standard error value. A second randomness assessment compares actual repeated values in the digital signal against expected repeated values. An information processing system continues processing the signal if the assessments indicate the possibility of an information component.

Abstract: A first communication device receives a communication from a second communication device. The communication could be part of the signaling used to establish a call to the second communication device or an audio signal that the second communication device conveys after its user has answered the call and started speaking. Based on the communication from the second communication device, the first communication device provides a user-discernible indication regarding the environment in which the second communication device is being used, such as an indication that the second communication device is being used with a speakerphone. If the second communication device is being used in a vehicle, the first communication device may also provide a user-discernible indication regarding the operational status of the vehicle, such as whether the vehicle is in motion and/or the number of occupants in the vehicle.

Abstract: Apparatus for reducing FM click noise on a demodulated FM signal, the apparatus comprising, filter means configured to produce a click detection signal according to the demodulated FM signal, click detection means configured to receive the click detection signal and produce a click occurrence signal, and click correction means configured to correct FM clicks on the demodulated FM signal according to the click occurrence signal.

Abstract: One aspect of the present invention is directed to an apparatus to perform impulse blanking of a received signal at multiple locations of a signal processing path. To effect such impulse blanking, multiple impulse detectors and blankers may be present, in addition to other circuitry. The impulse detectors may operate at different bandwidths, and the impulse blankers may be located at different locations of the signal processing path and may be differently configured.

Abstract: One aspect of the present invention is directed to an apparatus to perform impulse blanking of a received signal at multiple locations of a signal processing path. To effect such impulse blanking, multiple impulse detectors and blankets may be present, in addition to other circuitry. The impulse detectors may operate at different bandwidths, and the impulse blankers may be located at different locations of the signal processing path and may be differently configured.

Abstract: An exemplary signal interference control system is disclosed that utilizes a computer system, such as programmable logic circuits or computer controlled logic gates, to generate blanking or control signals for various types of radio frequency receiver and transmitter combinations. Control signals are generated based on signal characteristic information stored in a memory including a delay following receipt of a pre-trigger signal from a radio frequency transmitter and a pulse width of control signal(s) generated for specified receivers, frequencies or systems. In one embodiment, information can be retrieved from a memory and used to generate an interference control signal. One or more control signals can be routed to a related or associated receiver to reduce or eliminate interference effects.

Abstract: Antenna noise temperature is determined for a handheld wireless communication device which typically includes a radio, e.g. having a wireless transceiver and associated circuitry connected thereto, and an antenna connected to the radio. The method includes measuring an antenna thermal noise component, measuring a radio noise component, measuring an environmental background noise component, and determining the antenna noise temperature based upon the measured antenna thermal noise, radio noise, and environmental background noise components. The method may include measuring antenna efficiency, and determining further includes weighting at least one of the measured antenna thermal noise, radio noise and environmental background noise components based upon the measured antenna efficiency.

Abstract: A split delay-line oscillator for secure data transmission is disclosed. In one embodiment, an apparatus for a split delay-line oscillator for secure data transmission includes a first modulator/demodulator block in a first device, the first modulator/demodulator block operable to insert a first variable delay to modulate a frequency of a shared carrier signal passing through the first modulator/demodulator block, and a second modulator/demodulator block in a second device, the second modulator/demodulator block operable to insert a second variable delay to modulate the frequency of the shared carrier signal passing through the second modulator/demodulator block, wherein the first and second devices create a shared secret by contributing data on the frequency-modulated shared carrier signal.

Abstract: One aspect of the present invention is directed to an apparatus to perform impulse blanking of a received signal at multiple locations of a signal processing path. To effect such impulse blanking, multiple impulse detectors and blankets may be present, in addition to other circuitry. The impulse detectors may operate at different bandwidths, and the impulse blankers may be located at different locations of the signal processing path and may be differently configured.

Abstract: Antenna noise temperature is determined for a handheld wireless communication device which typically includes a radio, e.g. having a wireless transceiver and associated circuitry connected thereto, and an antenna connected to the radio. The method includes measuring an antenna thermal noise component, measuring a radio noise component, measuring an environmental background noise component, and determining the antenna noise temperature based upon the measured antenna thermal noise, radio noise, and environmental background noise components. The method may include measuring antenna efficiency, and determining further includes weighting at least one of the measured antenna thermal noise, radio noise and environmental background noise components based upon the measured antenna efficiency.

Abstract: A noise blanker circuit and method of removing impulse noise from a signal and correcting the signal is provided. The circuit includes a detection stage, a pulse removal stage, and a pulse removal correction stage. The detection stage includes at least an input that emits an input signal along a first signal path and a second signal path. The first and second signal paths are in communication with a blank pulse generator. The pulse removal stage is in communication with the input and includes at least a sample and hold device that samples and holds the input signal based upon an output of the blank pulse generator. The pulse removal correction stage includes at least a pulse removal device in communication with the detection stage and the pulse removal stage and corrects the input received from the pulse removal stage based upon the output of the blank pulse generator.

Abstract: A method of channel allocation in a cellular communication network wherein a radio channel is to be selected for establishment of a connection in an environment with potentially interfering signals, the method comprising: establishing a radio channel candidate; processing the radio channel candidate with potentially interfering signals and calculating a carrier to interference ratio (CIR) for the selected carrier frequency of the radio channel candidate and the potentially interfering signals; calculating a dominant interference ratio (DIR) being the ratio of the strongest potentially interfering signal with respect to the other potentially interfering signals; and using criteria based on at least one of the dominant interference ratio and the carrier to interference ratio in a selection process for selecting a channel for the connection to be established.

Abstract: An AM receiver including an AM demodulator for demodulating an AM signal received by an antenna coupled to the AM demodulator is provided. The AM receiver further includes a bandpass filter for receiving the demodulated signal and generating a bandpass filtered signal. The AM receiver further includes a moving average filter for receiving the bandpass filtered signal and generating a moving averaged signal and a highpass filter for receiving the moving averaged signal and generating a highpass filtered signal. The AM receiver further includes an averaging filter for receiving the highpass filtered signal and generating an averaged signal and a summer for receiving the averaged signal and the highpass filtered signal and generating a difference signal. The AM receiver further includes a comparator for generating a noise blanking signal based on a comparison of the difference signal with a threshold.

Abstract: Methods are provided for reducing impulse noise effects in a motor vehicle radio. One method includes the steps of first detecting impulse noise received by the motor vehicle radio. The received impulse noise is classified as either short pulse width impulse noise or as long pulse width impulse noise. The short pulse width impulse noise can generally be blanked without seriously affecting the audio quality of the radio. For the long pulse width impulse noise, a maximum long pulse width blanking repetition rate is set and such impulse noise pulses are blanked at a blanking rate less than the maximum long pulse width blanking repetition rate.

Abstract: An embodiment is a receiver for a communications system that may substantially block unwanted signals in a frequency range to protect the receiver from overload. Simultaneously, the receiver of an embodiment substantially passes a desired signal so that its information may be processed by the, for example, communications system of which the receiver is part.

Abstract: 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 burst having a burst interval and separated by an inter-burst interval. A symbol can be transmitted from the communications terminal to the burst radar transceiver. The symbol has a symbol period that is substantially longer than a radar transceiver burst period comprising the burst interval and the inter-burst interval. Symbol energy can be accumulated during inter-burst intervals at the burst radar transceiver over a plurality of burst periods for approximately the symbol period.

Abstract: Antenna noise temperature is determined for a handheld wireless communication device which typically includes a radio, e.g. having a wireless transceiver and associated circuitry connected thereto, and an antenna connected to the radio. The method includes measuring an antenna thermal noise component, measuring a radio noise component, measuring an environmental background noise component, and determining the antenna noise temperature based upon the measured antenna thermal noise, radio noise, and environmental background noise components. The method may include measuring antenna efficiency, and determining further includes weighting at least one of the measured antenna thermal noise, radio noise and environmental background noise components based upon the measured antenna efficiency.

Abstract: A mobile device is provided that includes a digit input that can be manipulated by a user's fingers or thumb, an air conduction microphone and an alternative sensor that provides an alternative sensor signal indicative of speech. Under some embodiments, the mobile device also includes a proximity sensor that provides a proximity signal indicative of the distance from the mobile device to an object. Under some embodiments, the signal from the air conduction microphone, the alternative sensor signal, and the proximity signal are used to form an estimate of a clean speech value. In further embodiments, a sound is produced through a speaker in the mobile device based on the amount of noise in the clean speech value. In other embodiments, the sound produced through the speaker is based on the proximity sensor signal.

Abstract: 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 insufficient, the circuit having: a squelch detecting circuit detecting the existence of a signal on a communication line in response to a transmission signal or a received signal and generating a first squelch signal; and a squelch control circuit generating a squelch mask signal in response to the first squelch signal and a transmission control signal and generating a second squelch signal based on the squelch mask signal and the control signal. The first squelch signal is controlled by the transmission signal to generate the second squelch signal in which the lacked portion of the first squelch signal is temporally restructured.

Abstract: A noise blanker circuit and method of removing impulse noise from a signal and correcting the signal is provided. The circuit includes a detection stage, a pulse removal stage, and a pulse removal correction stage. The detection stage includes at least an input that emits an input signal along a first signal path and a second signal path. The first and second signal paths are in communication with a blank pulse generator. The pulse removal stage is in communication with the input and includes at least a sample and hold device that samples and holds the input signal based upon an output of the blank pulse generator. The pulse removal correction stage includes at least a pulse removal device in communication with the detection stage and the pulse removal stage and corrects the input received from the pulse removal stage based upon the output of the blank pulse generator.

Abstract: A noise blanker for use in a radio receiver includes an audio blanker (115) configured to mitigate impulse noise associated with a signal received by the radio receiver and a blanker controller (117) configured to selectively enable the audio blanker and further comprising at least a first blanker enabler and a second blanker enabler. The noise blanker controlled and corresponding method (500) can include a first noise detector, e.g., MPX noise detector (213), configured to provide a first signal when impulse noise is detected in a demodulated signal and a second noise detector, e.g., log RSSI noise detector (211), configured to provide a second signal when impulse noise is detected in a modulated signal, and a logic function (217) coupled to the first and second signals and configured to provide an enable signal to the noise blanker when the first signal or the second signal is provided. Note that in addition to or in lieu of either of the noise detectors, a switching enabler (215), responsive, e.g.

Abstract: An apparatus and method for controlling a volume of comfort noise in a mobile communication terminal. The mobile communication terminal includes a vocoder for detecting a decoding rate of voice data received after establishing a voice call to output a detection signal and an amplifier for amplifying an output signal of the vocoder. The method comprises the steps of determining whether the decoding rate of the voice data from the vocoder is ?, recognizing the voice data as silence period data containing only the comfort noise and providing the vocoder with a control signal to lower a volume of the comfort noise, if the decoding rate of the voice data is ?, and controlling a volume of the voice data such that it becomes a volume preset by a user, if the decoding rate of the voice data is not ?.

Abstract: An auto-zero circuit is disclosed. The auto-zero circuit includes a first set of circuits for implementing a first auto-zero phase and a second set of circuits for implementing a second auto-zero phase. The first set of circuits includes a first differential amplifier and a first feedback path coupled between an output of the first differential amplifier and an input of the first differential amplifier. The second set of circuits includes a second differential amplifier and a second feedback path coupled between an output of the second differential amplifier and an input of the first differential amplifier, where the second feedback path includes an attenuation capacitor for reducing charge injection error and noise error of the auto-zero circuit and a holding capacitor for holding a voltage to be used to correct charge injection error introduced by the first feedback path.

Abstract: 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 pre-processes the positive and negative signals of an input signal to generate four pre-processed signals that are paired and sent to the low swing pre-amplifier. The outputs of the low-swing pre-amplifier are then over-sampled by the sampling and decision circuit. Multi-phase clocks are used to control the over-sampling in the sampling and decision circuit. A logic circuit then determines if the state of the input signal based on multiple samples.

Abstract: A digital blanking circuit allows a first digital input signal transition to be passed on to a following stage, but prohibits the passing of subsequent transitions for a predetermined blanking interval. One embodiment of the present invention employs rising edge and falling edge latches, the inputs of which receive the digital input signal and the outputs of which are connected to a two-to-one multiplexer. The mux output is connected to a blanking interval circuit, which is triggered to begin timing a blanking interval by a multiplexer output transition. The blanking interval circuit provides outputs which control the latches and selects the latch output to be transferred to the multiplexer output such that the multiplexer output is prevented from transitioning during a blanking interval.

Abstract: A method of masking interruptions in the playback of received radio signals is provided, in which lengthy interruptions are allowed only when modulation of the radio broadcast program currently being received is recognized as speech, and a modulation pause in the received radio signal is detected. This method permits essentially complete masking of lengthy interruptions in playback or making them inaudible, in which these interruptions are necessary, e.g., for analysis/testing for a transmission frequency of transmitted RDS information to be used as an alternative to a transmission frequency currently being received.

Abstract: An improved noise reduction system (20) is provided for a radio frequency audio processor having one or more weak signal processing components for generating one or more corresponding control values (36a, 36b) for controlling characteristics of the audio output from the processor, and a blanking pulse generation component (10) for generating a blanking pulse signal (18) in relation to an impulse noise signal imposed on the radio frequency signal. The improvement (20) can include at least one detector (30a, 30b) for determining a state value of the blanking pulse signal, such as the pulse density or frequency. At least one alignment function module (32a, 32b) is provided that is operable on the state value to generate at least one corrected control value corresponding to one of the weak signal processing components.

Abstract: A diversity reception handset includes a receiver for receiving pilot and plural increments of traffic sent from a base station within a service area of a wireless communications network. The handset includes at least two antennas, a switch for switching a receiver between the two antennas, a time-of-arrival searcher circuit connected to the receiver and responsive to the pilot for determining time of arrival of the received signals and expected time of arrival of each increment, and a controller for controlling the switch based upon determined expected time of arrival of each increment.

Abstract: An impulse noise reducer detects impulse noise in an audio signal by detecting and smoothing the high-frequency amplitude of the audio signal, attenuating the non-smoothed amplitude according to the smoothed amplitude, and comparing the attenuated amplitude with a threshold. Impulse noise is discriminated from high-frequency audio components because the latter tend to occur in longer-lasting bursts and are therefore attenuated more strongly. The impulse noise reducer is simplified because it does not have to perform intermediate-frequency signal processing, and its sensitivity is not affected by adjacent-channel signals because these signals are substantially absent from the audio signal. The impulse noise reducer can be implemented by digital signal processing, and is suitable for use in a medium-wave AM audio broadcast receiver.

Abstract: A noise reducer generates a gate signal by detecting noise in a demodulated signal, and changes the lengths the gate pulses indicating the presence of noise according to the electric-field strength of a radio signal from which the demodulated signal has been obtained. The demodulated signal is modified during intervals indicated by the gate pulses, to reduce the noise. The amount of change of the gate-pulse lengths is preferably increased as the electric-field strength decreases. Noise can then be removed satisfactorily under even weak electric-field conditions.

Abstract: 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 gate receives the input signal and it passes or blocks the signal depending upon the state of the signal received from the switched circuits. When it is passing the input signal, the output of the gate is equivalent to the input signal. When it is blocking the input signal, the output of the gate is set to a default state. The default state is independent of the input signal. One of the switched circuits gradually modifies the signal provided by the gate to allow the input signal to pass through. The other switched circuit gradually modifies the signal provided to the gate to block the input signal.

Abstract: 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 from a wireless microphone.

Abstract: 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 detected signal due to atmospheric conditions and the noise due to the gain in noise figure properties of the circuitry. The output of the noise estimator is used to calculate a threshold signal (50) and another detection operation (52) determines whether the power of a signal derived from the detected signal exceeds the threshold. If the threshold is exceeded, the detected signal is passed through a signal conditioner, such as a switch (54) to an output path (56).

Abstract: A radio back-end integrated circuit that includes a blanking switch having a signal input which receives an IF signal, a control input, and a signal output. Also included is a demodulator having an input coupled to the output of the blanking switch, and an output. The radio back-end also has a sample and hold switch having a signal input coupled to the output of the demodulator, a control input, and an output. Combined with the switch is a noise impulse detector having an input coupled to the IF signal and an output coupled to the control inputs of the blanking switch and the sample and hold switch. A sample and hold/de-emphasis circuit has an input coupled to the output of the sample and hold switch, and an output. The sample and hold/de-emphasis circuit has a high input impedance amplifier, a resistor, and only one capacitor.

Abstract: A receiver portion of a telephone includes a differential amplifier stage with a single output, an electroacoustic transducer connected between the output, via a capacitor and ground and a unit for controlling switching on/off, connected to the differential stage for the activation or deactivation thereof. To prevent annoying noises in the transducer upon switching on and off, the differential stage includes an operational amplifier having a first capacitor and a second capacitor in series with the inverting and the non-inverting input terminals. A third capacitor is connected between the inverting input and the output of the operational amplifier. A fourth capacitor is connected between the non-inverting input and a first reference-voltage terminal. A first switching capacitor is alternatively connectable between a second and a third reference-voltage terminal, or between the first input and the output of the operational amplifier.

Abstract: A digital noise reduction for a radio frequency receiver communication systems that is field programmable to function with a large variety of signaling schemes or waveforms. The noise reduction arrangement includes circuits to convert the mulit bit digital signal (including noise impulses therein) into logarithmic form and uses exponential averaging to determine the presence of noise and the magnitude thereof. Various threshold circuits, the exponential averaging circuits and an exponential decay circuit are responsive to digital commands to set the thresholds for noise detection and control when the noise should be blanked and the duration of blanking.

Abstract: A noise reducer generates a gate signal by detecting noise in a demodulated signal, and changes the lengths the gate pulses indicating the presence of noise according to the electric-field strength of a radio signal from which the demodulated signal has been obtained. The demodulated signal is modified during intervals indicated by the gate pulses, to reduce the noise. The amount of change of the gate-pulse lengths is preferably increased as the electric-field strength decreases. Noise can then be removed satisfactorily under even weak electric-field conditions.

Abstract: 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 request (405) of one of two types, performing a release (410) of a reset control (107) in response to the squelch check request, generating an integrated noise signal (106) having essentially no decay rate from the noise signal starting at the release of the reset control, generating a result of a comparison (815, 860) of the integrated noise signal to one of two values corresponding to the one of two types of squelch check requests at an expiration of a predetermined delay started at the release of the reset control, and controlling a muting (845, 870) of a speaker (128) in response to the comparison.

Abstract: A problem in hearing aids or other audio/acoustic amplifier circuits is that external sources of EM energy may be coupled into the electronics of the hearing aid so as to contribute to the acoustic output. The invention provides a circuit for removing the effects of EM interference. A separate reference generator is used to detect the external EM energy. This is fed into an interference canceller which may be adaptive, which effectively removes the unwanted component in the hearing aid signal, leaving only a signal representative of the desired acoustic output.

Abstract: 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 temporarily operates in a second operating mode which has receiver parameters selected to reduce carrier detect falsing when compared to the first operating mode (430). Preferably, in the second operating mode, the receiver's frequency and time response characteristics are modified to facilitate carrier squelch detection. Carrier squelch is performed if a carrier signal detect is triggered while the receiver operates in the second operating mode (440, 450, 460, 470).

Abstract: In methods and apparatus for generating an LPC-encoded noise signal from an LPC-encoded speech signal, excitation parameters of the LPC-encoded speech signal for a current frame are randomized upon detection of speech in the current frame. For frames in which no speech is detected, LPC coefficients and frame energy for the current frame may be replaced with respective averages calculated over the current frame and a plurality of preceding frames. For frames in which speech is detected, LPC coefficients for the current frame may be replaced with respective averages of LPC coefficients used to replace LPC coefficients of an immediately previous frame. The comfort noise generation technique is particularly suitable for use in echo suppressors for digital cellular radio systems.

Abstract: A method and apparatus for suppressing noise in a radio receiver or the like due to electromagnetic interference generated by the firing of a spark plug which coordinates the operation of a noise blanker with the EST signal generated by an electronic engine control module or similar spark timing signal. The apparatus of the present invention comprises a noise blanker disposed within a radio receiver for blanking the output of the radio receiver for a predetermined duration after a predetermined time delay has elapsed after each EST signal pulse. The noise blanker is activated for a time duration slightly longer than the duration of the impulse noise. The noise blanker may also be designed to be deactivated when the desired signal level reaches a predetermined level. The apparatus of the present invention may be used in conjunction with other noise suppression systems to eliminate noise due to sources other than the electronic ignition system.

Abstract: A method and apparatus to enable high-quality digital transmissions to a satellite terminal operating in proximity to a radar source combines interleaving a sequence of channel symbols at a land station before transmission of an RF signal to a satellite, increasing the satellite's EIRP to compensate for the effects of the radar's duty factor on received signal power and code distance, detecting the radar pulses at a satellite terminal, blanking the received RF signal to prevent reception of the signal by the modem at the satellite terminal during the radar's ON time, having the modem recognize and eliminate the effect of the gap in the channel signals on its metric calculation, and de-interleaving the sequence of channel symbols. As a result, satellite terminals operating in proximity to radar sources can provide the same quality of service as if there were no radars operating.

Abstract: A circuit arrangement for brief mute switching of the reproduction of an LF signal in a radio receiver for performing additional control operations is described, in which the mute switching is effected by varying the current flow through the control path of an interrupter by means of a reversing switch, as a consequence of the change in charge of a capacitor acted upon by a blanking signal.

Abstract: A system for eliminating the effects of transmission errors in a digital stream is characterized by the presence of a predictor. The output signal of this system is taken from a predicted signal during the presence of errors and from the received signal when the errors are not present.