Abstract: A method for managing the operation of an object capable of contactless communication with a reader magnetically coupled to the object includes a phase for transmission of information from the object to the reader and includes a modulation of the impedance of a load connected across the terminals of the antenna of the object. Prior to the transmission phase, a monitoring phase includes a monitoring of the level of amplitude modulation of a modulated test signal present at the antenna of the object and resulting from a test modulation of the impedance of the load and a capacitive modification of the impedance of the load if this level is lower than a threshold.

Abstract: Various embodiments manage a distributed audio system is disclosed. In one embodiment, an audio stream is received from each electronic device in a plurality of electronic devices. The audio stream is captured by at least one audio input module of the electronic device. Two or more of the audio streams are aggregated into a single audio stream. The single audio stream is outputted via at least one audio output module.

Abstract: Systems, methods, apparatus, and articles of manufacture to provide for low-latency delivery and playback of audio are disclosed. In one embodiment, an example audio system includes multiple playback devices including a primary device and one or more secondary devices, whereby, the primary device establishes and controls a peer-to-peer network that connects, wirelessly or wired, to each of the satellite devices. An example audio device contains a channel selector, a control interface, and an audio interface. In some embodiments the control interface is used to transmit control information to another device on a first frequency channel, and the audio interface is used to transmit audio information to another device on a second frequency channel.

Abstract: Methods and devices for determining whether a head-mountable computing device is donned or doffed are disclosed. In one embodiment, a method is disclosed that includes receiving from at least one capacitive sensor data indicating a rate of change of capacitance, making a comparison of the rate of change of capacitance to a threshold rate of change of capacitance and, based on the comparison, determining whether the head-mountable computing device is donned or doffed. The method further includes, if the head-mountable computing device is donned, causing the head-mountable computing device to operate in a first state, and if the head-mountable computing device is doffed, causing the head-mountable computing device to operate in a second state, where the head-mountable computing device consumes less power in the second state than in the first state.

Abstract: In an audio network system constructed from a main node and a plurality of satellite nodes each having a plurality of ports, the main node generates and transmits a main packet including audio signals of a plurality of channels. Each satellite node selects one of the plurality of ports in turn, and confirms whether the main packet arrives at the selected port every predetermined period or not. When the main packet arrives at the selected port every predetermined period, the main packet is received via the port by continuing selection of the port. In the case where reception of the main packet is lost, one is selected from the plurality of ports in turn, the operation to confirm arrival of the main packet is restarted, and another port at which the main packet arrives at the present stage is automatically found.

Abstract: Method, apparatus and computer program product for processing an input stereophonic audio signal to thereby generate a converted stereophonic audio signal representing the input stereophonic audio signal, the input stereophonic audio signal comprising a left input audio signal and a right input audio signal, and the converted stereophonic audio signal comprising a first converted audio signal and a second converted audio signal. The first converted audio signal is generated based on the sum of the left input audio signal and the right input audio signal. The second converted audio signal is generated based on the difference between a first function of the left input audio signal and a second function of the right input audio signal. The first and second functions are adjustable to thereby adjust at least one characteristic of the converted stereophonic audio signal.

Abstract: A wireless audio device may realize power savings when processing multi-channel data, e.g. 2-channel stereo audio data, by splitting the multi-channel block data into separate data blocks for each channel, e.g. Left-channel data block and Right-channel data block, and processing each separate data block independently in the source device to generate respective data packets targeting corresponding sink devices, e.g. a Left earphone and a Right earphone. The source device may then transmit each data packet to a different corresponding sink device, e.g. a Left-channel packet to a Left earphone and a Right-channel packet to a Right earphone. The data packets may also include header information indicative of whether a next packet is intended for a given sink device, enabling sink devices to enter sleep mode when the header information indicates that a next packet is not intended for the given sink device, to save power.

Abstract: The invention provides a noise removal device and method capable of more proper interpolation on an input signal. The noise removal device is for removing noise in an input signal and includes: a noise detector detecting noise in an IF signal and outputting a noise detection signal; an interpolation controller determining a period and amount of interpolation for noise correction processing, based on the IF signal and the noise detection signal; and a noise gate processor performing the noise correction processing on the IF signal, based on the interpolation period and amount supplied from the interpolation controller. The interpolation controller sets a predetermined first interpolation period, based on a first noise detection signal inputted from the noise detector, and redefines a second interpolation period longer than the first interpolation period when a second noise detection signal is detected within the first interpolation period.

Abstract: A sending method includes supplying a material to a plurality of audio channels that send an entirety of a music title repeatedly for a certain unit of time. The method also includes supplying digital data for forming an audio information screen associated with an audio channel being sent. The method additionally includes supplying audio data for downloading, which is compressed in a certain compression format. Further, the method includes multiplexing the entirety of the music title repeatedly sent using the plurality of audio channels, which is supplied in the supplying the material step, the digital data for forming the audio information screen associated with the audio channel being sent, which is supplied in the supplying the digital data step, and the audio data for downloading supplied in the supplying the audio data step. In addition, the method includes sending the multiplexed data.

Abstract: A ground station multiplexes audio digital data of a plurality of audio broadcasts, GUI data, and download audio data and transmits the multiplexed signal to a receiving side through a satellite. The receiving side displays a GUI screen corresponding to an audio broadcast. When a music information selection command is input on the display screen, and audio broadcast of a music program corresponding to the music information is selected. When a music information download command is input on the display screen, download audio data corresponding to the music information is output. The download audio data is stored to a storage device so as to download audio data corresponding to a desired music title.

Abstract: A stereo decoder and a method therefor are provided. The stereo decoder receives a MPX signal from an FM demodulator, and comprises a first auto-calibration circuit, a band-pass filter, a second auto-calibration circuit, a slicer and a PLL circuit. The first auto-calibration circuit generates a first control signal. The band-pass filter generates the pilot signal by filtering the MPX signal with a center frequency set by the first control signal. The second auto-calibration circuit generates a second control signal. The slicer converts the pilot signal into a square wave signal. The PLL circuit comprises a voltage controlled oscillator for generating an oscillation frequency in response to the second control signal. The PLL circuit receives the square wave signal to generate the reference signal around the predetermined frequency in response to the oscillation frequency.

Abstract: A transmitting/receiving method that can easily detect an influence exerted in transmission channels at a transmitter/receiver is provided. An acquiring unit 12 acquires left audio data and right audio data of audio data received by a metadata calculator 1. An adding unit 141 then calculates added data based on an added value for a predetermined time of a sum of the acquired left audio data and right audio data. Similarly, a subtracting unit 142 calculates subtracted data based on an added value for predetermined time of a difference between the acquired right audio data and left audio data. An addition unit 17 adds the added data and the subtracted data calculated by these adding unit 141 and subtracting unit 142 to the received audio data, and a transmission unit 18 transmits the audio data to which the added data and the subtracted data are added.

Abstract: A parametric representation of a multi-channel audio signal describes the spatial properties of the audio signal well with compact side information when a coherence information, describing the coherence between a first and a second channel, is derived within a hierarchical encoding process only for channel pairs including a first channel having only information of a left side with respect to a listening position and including a second channel having only information from a right side with respect to a listening position. As within the hierarchical process the multiple audio channels of the audio signal are downmixed iteratively into monophonic channels, one can pick the relevant parameters from an encoding step involving only channel pairs carrying the information needed to describe the spatial properties of the multi-channel audio signal.

Abstract: An input signal is input via a first resistor to an inverting input terminal of an operational amplifier. A second resistor is provided on a feedback path between an output terminal and the inverting input terminal of the operational amplifier. A control voltage Vcnt output from the operational amplifier is input to a VCO. A frequency divider frequency-divides an output signal Sout of the VCO. A phase comparator compares an output signal from the frequency divider with a reference clock signal and outputs a voltage according to a phase difference. A loop filter removes a high-frequency component of an output voltage Vcp of the phase comparator and outputs the voltage to a non-inverting input terminal of the operational amplifier.

Abstract: A novel system and method for correcting the residual phase offset between a recovered pilot signal and the received stereo signal. The invention uses a Costas loop as an auxiliary loop in addition to the pilot recovery phase locked loop (PLL) to lock onto the stereo component itself. This auxiliary loop functions to generate a pilot to stereo component phase correction signal that is added to the stereo carrier phase The resultant phase is used to generate the recovered pilot carrier used to demodulate the stereo MPX signal. The Costas loop is activated together with the main pilot recovery PLL that locks onto the pilot tone in the demodulated MPX signal. The auxiliary Costas loop is operative to track and determine a residual phase error of up to several degrees.

Abstract: A method of removing noise and interference from a signal by receiving the signal, calculating a joint time-frequency domain of the signal, estimating instantaneous frequencies of the joint time-frequency domain, modifying each estimated instantaneous frequency, if necessary, to correspond to a frequency of the joint time-frequency domain to which it most closely compares, redistributing the elements within the joint time-frequency domain according to the estimated instantaneous frequencies as modified, computing a magnitude for each element in the joint time-frequency domain as redistributed, plotting the results as the time-frequency representation of the signal, identifying in the plot any noise and interference components in the received signal, eliminating from the redistributed joint time-frequency domain elements that correspond to noise and interference, and recovering a signal devoid of noise and interference from the modified redistributed joint time-frequency domain.

Abstract: A method in a portable communication device for displaying information includes encoding data and transmitting the encoded data to a display associated with a vehicle. The encoded data is received by a receiver associated with the display, decoded and displayed.

Abstract: A wireless headphone device may include a receiver for receiving a wireless digital signal containing a plurality of digital audio streams combined with control codes according to a predetermined format, a manually operated selector switch for selecting one or more of the plurality of digital audio streams to be produced as audio for the user, and a decoder for extracting the selected audio streams from the received signal in accordance with the predetermined format and for responding to the control codes in the received signal to perform predetermined functions.

Abstract: Disclosed herein is a portable charger for mobile phones and other consumer electronic devices like iPOD, MP3 players, etc. The portable charger is a plug-and-charge device, it includes both male and female connectors, built-in rechargeable Li-Polymer or Li-Ion battery, LED and ON/OFF button. USB-flash-drive like design with cap covering male connector, lightweight enough to be attached to a key chain, when is needed, it can be plugged into Cell phone or other portable devices to charge devices right away. In various embodiments, different functionalities are added: utility light, MP3 player, FM radio transmitter, FM radio receiver, Bluetooth audio adapter, voice recorder, USB flash drive.

Abstract: Apparatus and method for transmitting and reproducing stereophonic audio signals are disclosed. The method comprises splitting first and second channels into two frequency bands, combining the lower frequency band signals of the two channels, and transmitting the combined signals of the two channels or signals representative thereof. The apparatus comprises: a splitter for splitting each of the two channels into two frequency bands, a combiner, for combining the lower frequency band signals of the two channels, and a transmitter for transmitting the combined signals, or signals representative thereof, and the higher frequency band signals of the two channels, or signals representative thereof.

Abstract: A stereo modulator converts an audio signal to a stereo composite signal. A frequency modulator receives the stereo composite signal and modulates the frequency of a carrier wave using the stereo composite signal as a modulation signal. An amplitude modulator modulates the amplitude of a sub-carrier by using, as a modulation signal, a difference signal between an L-channel and an R-channel of the audio signal. A first adder adds an output of the amplitude modulator with a sum signal of the L-channel and R-channel. A first multiplier multiplies an output of the first adder with a first variable coefficient. A second multiplier multiplies a pilot signal with a second variable coefficient. A second adder adds outputs of the first and second multipliers and outputs the resultant. A modulation degree adjuster adjusts the amplitude of the stereo composite signal and outputs the resultant signal to the frequency modulator.

Abstract: A wireless audio distribution system may have a wireless transmitter, responsive to a plurality of audio input channels, for transmitting signals carrying the audio, a receiver, responsive to the transmitted signals for selecting one or more of the audio input channels to be reproduced in accordance with local setting selectors at the receiver. An additional audio source, such as a microphone, can be selectively used by for example the driver to talk on the cell phone or to make announcements to passengers via the wireless audio distribution system in accordance with a master settings selector which may be used to override local settings such as audio channel or volume selection.

Abstract: A method and system is disclosed for transmitting two related channels of signals through the air. A first channel of signals is modulated with a first carrier frequency, and a second channel of signals is modulated with a second carrier frequency. The modulated first channel of signals and the second channel of signals are then combined through a high isolation combiner. Thereafter, the combined signals are transmitted toward a receiver system. After receiving the transmitted signals, the first channel and the second channel of signals are regenerated in the receiver system by separating one from the other.

Abstract: A stereo decoding system comprises an oscillator, a bandpass filter, a PLL unit and a stereo decoder. The oscillator generates a first signal with a center frequency. The bandpass filter receives a stereo multiplexed signal and the first signal to filter out a pilot signal. The PLL unit receives the pilot signal to generate a PLL output signal. The stereo decoder receives the stereo multiplexed signal and the PLL output signal to separate a left channel signal and a right channel signal from the stereo multiplexed signal.

Abstract: A wireless audio distribution system may include a wireless transmitter transmititing an encoded digital bitstream serially combining each of a plurality of audio input channels and control data, a wireless receiver receiving the transmitted bitstream, a manual selector switch to for selecting one or more of the audio input channels and a sound producing device reproducing the selected audio channels in accordance with the control data. A system may include a wireless receiver receiving an encoded digital bitstream combining each of a plurality of audio input channels with control data disbursed therein, a manual selector switch for selecting audio input channels and a sound producing device for selectively decoding and demultiplexing the selected audio channels to be reproduced in accordance with the control data.

Abstract: To retrieve RDS information by filtering and transforming an incoming multiplex signal (m(t)) into a RDS baseband signal, an amplitude modulated RDS signal (ma(t), mc(t)) is derived on basis of an intermediate signal (ma(t)) obtained during an extraction of a stereo-difference signal (md(t)) from the incoming multiplex signal (m(t)).

Abstract: A computer system provides a wireless audio signal transmitter module which is capable of transmitting audio signal wirelessly from a host computer to at least one remote wireless signal receiver. The wireless audio signal transmitter module is connected to a sound effect interface for receiving audio signal from the computer. The audio signal is processed, modulated, and then transmitted out by an antenna. The wireless signal is received and processed by the audio signal receiver located within an effective transmission distance. The signal is then transmitted to a user via a microphone.

Abstract: A wireless audio transmission apparatus and method for coupling audio players to audio receivers for broadcast of audio signals stored in and processed by the audio player. A housing carrying operative circuitry is electrically connected by a multiconductor cable to an audio player for receiving stereo channel signals. Band pass filters couple the stereo signal and signal ground conductors in the cable to the stereo encoder in the housing. The filtered stereo signals are received by a stereo encoder in the housing and modulated onto a radio frequency carrier signal. A transmitter coupled to an antenna carried in the cable wirelessly transmits the carrier signal and the audio signals to a remote radio frequency receiver for demodulation and broadcast of the audio signals. Preferably, the carrier signal is an FM radio frequency signal. The carrier signal is optionally selectable from a plurality of different carrier signal frequencies.

Abstract: A wireless transmission device for communicating a plurality of audio streams to remote devices may include a plurality of inputs for receiving a plurality of digital audio streams, a combiner connected to the inputs for combining control codes and the received audio streams in a predetermined format to form a signal wherein the control codes for controlling the operation of a remote device equipped for processing the signal to extract the audio streams therefrom in accordance with the predetermined format, and a transmitter connected to the combiner to transmit the signal for reception by the remote device. The transmitter may include an infra-red light emitter for transmitting the signal as an infra-red light signal.

Abstract: A wireless audio distribution system having a wireless transmitter, responsive to a plurality of audio input channels, for transmitting a encoded digital bitstream serially combining each of the audio input channel, the encoded digital bitstream further including control data disbursed therein, a receiver, responsive to the transmitted encoded digital bitstream, for decoding and demultiplexing the digital bitstream, a manual selector switch, connected to the receiver device for selecting one or more of the audio input channels to be reproduced, and a sound producing device for selectively reproducing the one or more selected audio channels in accordance with the control data.

Abstract: This invention is directed to a transmitting apparatus adapted for carrying out transmission of audio signals by using infrared rays and a reproducing apparatus using a headphone device adapted to receive audio signals transmitted from the transmitting apparatus to reproduce them. The transmitting apparatus allows digital audio signal to undergo time axis compression every unit time period, and to repeat the same contents to transmit such repetitive signals by infrared rays. The headphone device comprises a light receiving element for receiving infrared rays, and a memory adapted so that valid signals of the received repetitive signals are written thereinto and the written signals are caused to undergo time axis expansion and are read out therefrom to allow the signals which have been read out from the memory to undergo D/A conversion to deliver the signals thus obtained to speaker units of the headphone device to reproduce them.

Abstract: A multiple signal carrier transmission apparatus and method for broadcasting stereo sounds to an audio output device uses three related carrier frequencies on which are modulated the sum of first and second stereo channel signals and the first and second stereo channel signals themselves. The composite multiple carrier frequency signal is transmitted to a receiver which separates the three carrier frequency signals to generate a separate left channel signal, a right channel signal and a composite center channel, monophonic, signal which is the sum of the first and second channel signals. A detector monitors the signal strength of each separate left and right channel signal to detect a decrease in either channel output below a threshold. When a decrease below the threshold is detected, the center sum signal replaces the left and/or right channel signal having the diminished signal strength for output through the appropriate speaker to minimize channel fade out.

Abstract: A method and apparatus for high fidelity duplexing, local transmission and reception of audio-signals transmitted from sources such as stereos, televisions, or musical instruments is taught. According to these teachings, high fidelity wireless stereophonic transmission system having a plurality of audio channels are realized. An oscillator is electrically connected to the first audio channel to provide a first carrier frequency upon which the data of the first audio channel is imposed. The first carrier frequency is then combined with a second audio channel's data forming a composite signal. The composite signal is then imposed on signal generated by a second oscillator. This second oscillator provides a carrier frequency for a frequency modulated (FM) transmitter. The signal from the FM transmitter is received by a receiver and the respective signal's of the two audio channels are demodulated and used to drive speakers.

Abstract: A feedback controller, embedded in an FM audio processor, that controls the “integrated multiplex power” to the requirements of ITU-R 412 (2.51) is disclosed. This regulation specifies the maximum power, which is the same as the power produced by a sinewave modulating the carrier ±19 kHz (where ±75 kHz is 100% peak modulation). The controller applies the square of the multiplex signal to an integrator. A constant is removed from the integrator; representing the maximum power threshold. The output of the integrator is sampled periodically with a sample-and-hold circuit. A second integrator receives the output of the sample-and-hold. The output of the second integrator circuit is added to the threshold setting of a compressor, which determines the average power output of the compressor. The output of the compressor is applied through a peak controller to the input of the multiplex coder, closing a feedback loop, which controls the integrated multiplex power to a preset threshold.

Abstract: According to the invention, a method for playing a streamed content object using hypertext transport protocol (HTTP) transport is disclosed. In one step, a first portion of the streamed content object is received from a packet switched network using HTTP. The first portion is played at least partially coincident in time with the first listed receiving step. A second portion of the streamed content object is received. The second portion is not contiguous in the streamed content object to the first portion.

Abstract: A wireless transmitter/receiver circuit system having a transmitter circuit and a receiver circuit, that enable a wireless headphone or speaker system to automatically trace floating frequency upon receiving of a transmitting signal, so as to achieve a quality receiving. The transmitter circuit includes a pilot oscillator and a 32K˜1 MHz selector, that are controlled to encrypt transmitting signal, enabling transmitting signal to be accurately received by the receiver circuit. The receiver circuit has a concealed receiving antenna installed in a metal shell for direct coupling by air, a pilot select, a digital logic and a scan driver for automatically scanning signal transmitted from the transmitter circuit, enabling transmitted signal from the transmitter circuit to be accurately provided to the headphone or speaker system.

Abstract: A transmitter for transmitting an audio signal derived from an audio appliance to an FM (frequency modulation) radio includes a transmitter circuit for converting the audio signal derived from an audio appliance into an FM signal within an FM broadcasting band to thereby transmit the FM signal, a receiver circuit having at least a tuner unit; a display for displaying thereon a frequency; and a control circuit for controlling a transmission frequency of the transmitter circuit and a reception frequency of the receiver circuit. The control circuit causes the receiver circuit to detect an unused frequency within the FM broadcasting band and to set a frequency corresponding to the detected unused frequency to the transmission frequency, and also causes the display to display thereon the set transmission frequency.

Abstract: A multiplex transmission device for multiple-channel signals, in particular multiple-channel audio signals, has a plurality of input channels, each of which receives an input signal, a multiplexer, the input channels being connected with the inputs of the multiplexer, and with an output channel which is connected to the output of the multiplexer for sending an output signal which is multiplexed from the input signals. A control element is connected in each input channel for controlling the amplitude of the respective input signal and a regulating device is provided for controlling the control elements. A special feature of the device consists in that the regulating device uses the output signal of the multiplexer as a regulating variable.

Abstract: A transmitter includes a plurality of oscillators for transmitting multiple radio frequency (RF) signals simultaneously, from each one of which signals a broadcast radio receiver system can reproduce the transmitted audio information. The transmitter will not only allow a user to listen to a CD or tape player through the radio receiver system but also let the user choose whichever frequency gives the best quality sound by merely tuning the receiver system in the same manner as tuning it to the broadcast radio station signals.

Abstract: A portable RF transmitter having an audio plug extending therefrom which mates with the earphone or output jack of an audio source such as a portable battery operated CD or tape player and having no external antenna. The portable RF transmitter modulates audio signals from the audio source onto an FM carrier and transmits them to an FM receiver mounted on a headset worn by a user. The RF transmitter uses its own ground circuit and the ground circuit of the audio source as two elements of a short dipole. The two ground circuits are electrically isolated at RF by an RF choke but connected together at audio frequencies by the low impedance of the choke at audio. The choke's leakage inductance also reduces the capacitive reactance of the dipole antenna for better power dissipation. A transformer coupling the RF output to the dipole transforms the impedance of the dipole to a value closer to the output impedance of the RF transmitter.

Abstract: A surround sound processor unit includes a plurality of preamplifiers, an in-phase audio decoder circuit, an out-of-phase audio decoder circuit, at least one transmitter, at least one receiver, at least one speaker amplifier, and a plurality of power amplifiers. A surround sound processor unit can take the stereo audio signal from a stereo VCR, a stereo receiver, a headphone jack, a stereo TV, or a car stereo to produce a three dimensional sound field. The left audio signal is amplified and outputed to a left front speaker. The right audio signal is amplified and outputed to a right front speaker. The in-phase audio decoding is accomplished by preamplifying the left and right audio signal, and connecting the output of the left and right preamplifiers to a singular input of a power amplifier. The output of the power amplifier drives a center channel speaker.

Abstract: A system for transmitting a main channel signal, a first subcarrier signal, and a second subcarrier signal includes a control signal generator for producing a control signal in response to the amplitude of the main channel signal and the first subcarrier signal, a modulator coupled to the control signal generator and generating the second subcarrier signal, a voltage controlled amplifier for providing the second subcarrier signal at an injection level that varies with the control signal, and a transmitter for transmitting the second subcarrier signal at the varying injection level.

Abstract: The FM stereo broadcasting apparatus has a sampling frequency converter for receiving a digital input signal having an L (left audio)-signal and an R (right audio)-signal and for converting the digital input signal so that its sampling frequency is equal to either a frequency of a subcarrier of a composite audio signal or a first sampling frequency of a first sampling signal for the operation of a composite audio signal generator, a sampling signal generator for generating the first sampling signal for the operation of the composite audio signal generator having the first sampling frequency which is equal to 2.sup.

Abstract: An analog spread spectrum wireless speaker system for use in consumer audio applications for providing reliable and high fidelity stereo sound. The system includes a transmitter that accommodates any analog input from a variety of audio devices such as compact disk players, cassette players, AM/FM tuners and transmits this information in the 2.4-2.4835 GHz band to a receiver at a remote location. The receiver is capable of reproducing the audio signal with good frequency and signal-to-noise performance.

Abstract: A simple and effective stereophonic transmission system (1) wherein the transmitter (2) alternatively encodes successive block periods of a block signal with samples of the left-hand channel signal (L.sub.in) and the right-hand channel signal (R.sub.in). At receiver side, the left-hand and right-hand stereo signals are decoded from the encoded block signal by alternate integration and peak detection of positive and negative received pulses, the pulse widths of the received pulses corresponding to amplitudes of the transmitted samples. When detecting the pulses for one stereophonic channel, the corresponding other stereophonic channel is blocked.

Abstract: A system is provided which transmits either analog or digital data signals over the air. The system includes a transmitter and a receiver. The transmitter and receiver are arranged to transmit signals using a carrier signal having a high frequency such as in the range of 902-928 MHz. The transmitter and receiver are configured to provide for the transmission of two channels of stereophonic signals while maintaining high signal-to-noise ratios, good frequency response, and low distortion. To provide for the proper transmission of signals between transmitter 10 and receiver 12, these devices include oscillating circuits having ceramic resonators which provide a base frequency which is readily modulated to facilitate proper transmission of either analog or digital signals between the transmitter and receiver.

Abstract: A fuel dispenser having a controllable audio/video program display includes a fuel pump and delivery path, a program media display, and a prerecorded program and a multi-media controller to direct program signals to the program media display. Apparatus is included for recovering multi-media control signals embedded in the program signals in the prerecorded program including a detector for detecting predetermined portions of the program signals having embedded control signals and rerouting means for rerouting the control signals in the program signals to an output. The multi-media controller is coupled to the rerouting means to act on the program signals as directed to the media display.

Abstract: An FM audio system has an FM tuner, a CD player, a stereo modulator for modulating an audio signal from the CD player to produce a composite signal so as to be received by the FM tuner for reproducing the audio signal. A control circuit such as an automatic level controller is provided for controlling a level of the audio signal applied to the stereo modulator to such a level as to prevent tone quality of sound reproduced by the FM tuner from deteriorating.

Abstract: A transmission apparatus and method for transmitting stereo multiplexed audio signals from a received television signal having a horizontal frequency f.sub.H are provided. Right and left channel audio signals obtained by demodulation from the received television signal are added to form a first combined audio signal. The same signals are subtracted to form a second combined audio signal. A subcarrier is modulated with one of the first and second combined audio signals, the subcarrier having a frequency substantially equal to 3f.sub.H to form a subcarrier modulated audio signal. The other of the first and second combined audio signals is combined with the subcarrier suppressed signal to form a stereo multiplexed audio signal, and the stereo multiplexed audio signal is transmitted.

Abstract: This invention discloses a wireless compact disc stereo playback system for use in automobiles. An FM transmitter is employed which is connected at the output of a portable CD player, the FM transmitter thereby producing a stereo FM signal which is transmitted to be received by the automobile antenna. The automobile's FM system is tuned to play the output of the CD player through the FM radio system of the automobile. The output power of the FM transmitter and its bandwidth are selected so that the distance from the antenna to the FM transmitter will be sufficient to ensure effective sound production in standard automobiles and vans.