Personal, self-programming, short-range transceiver system

Abstract

A method for establishing a communication link between a transmitter and a receiver for the purpose of relaying audio material derived from an existing source to a user desiring to remain unencumbered by the source apparatus comprises the steps of placing: the receiver unit into physical contact with the transmitter unit, powering up both transmitter and receiver units, and waiting for an indication of process completion before setting the receiver unit in place. The transmitter unit searches for a free rf communication channel, initiates transmission of user-chosen audio material over permitted broadcast bands, and programs the receiver unit with information allowing it to receive on the same channel. The receiver unit is lightweight, worn in the outer canal of the ear or on the head in the conventional manner. The entire programming and transmission process takes place automatically without further user intervention. This method allows multiple users in proximity to receive their individually chosen source material or to enjoy a common transmission.

What is claimed is:  
     
         1 . A receiver unit or system comprising: 
 a means for receiving and demodulating frequency-, phase-, pulse-, or amplitude-modulated rf information;    a means for decoding said information to baseband to recover the encoded audio signal;    a method of generating and maintaining a local heterodyne frequency to accomplish said decoding;    a method of selecting the source of rf input signal from either of two sources, said sources being an rf signal at from the integral antenna or from an included input connector or contact;    a means for converting said audio signal to an acoustic transducer;    a means for incorporating the acoustic transducer within a earphone housing; and    a means for supplying necessary power to all circuitry.    
     
     
         2 . A base unit or transmitter system comprising: 
 a means for modulating a preselected rf carrier frequency by an audio input signal, said means being either phase, frequency, pulse, or amplitude modulation;    a means for transmitting said modulated carrier;    a method of selecting said carrier frequency;    a means for generating said carrier frequency by means of a frequency synthesizer,    a means for monitoring and charging the earphone batteries of  claim 1;  and    a method of establishing the local heterodyne frequency of  claim 1 .    
     
     
         3 . The method of  claim 2 , wherein said selection method subdivides the frequency band into a plurality of bands, one of which, sufficiently free of interference, is chosen for transmission by the apparatus of  claim 2 .  
     
     
         4 . An apparatus of  claim 3  wherein said subdivision is accomplished by a swept, voltage-controlled oscillator, said sweep lasting a predetermined duration or until such time as a suitable channel has been located.  
     
     
         5 . An apparatus of  claim 3  wherein said subdivision is accomplished by a digital frequency synthesizer commanded by incrementing a digital counter integral to said digital frequency synthesizer, said counter being incremented until a suitable channel has been located.  
     
     
         6 . An apparatus of  claim 3  wherein said frequency band is chosen based on the signal level present in a particular bandwidth range said bandwidth range being selected by the method of  claim 3 , the selected frequency being applied to a mixer that mixes said selected frequency with the signal received by the antenna of the apparatus of  claim 2 . The output of said mixer being filtered and compared to a predetermined level. The criterion for selection of said frequency band being that said output be lower than said predetermined level.  
     
     
         7 . A method of commanding or programming the apparatus of  claim 1  to cause said apparatus to start receiving on the frequency band selected by the apparatus of  claim 2 .  
     
     
         8 . An apparatus of  claim 7  for causing a command signal from the apparatus of  claim 2  to the apparatus of  claim 1  and information describing the carrier frequency from the apparatus of  claim 2  to the apparatus of  claim 1  by means of a common contacts between said apparatuses, said command signal being a logic level and said descriptive information being a sample of the output of the carrier frequency generated by the frequency synthesizer of  claim 2 .  
     
     
         9 . An apparatus of  claim 8 , said command signal being a logic level of sufficient duration and said descriptive information being a binary code describing said carrier frequency, the length of said descriptive information presented to the apparatus of  claim 1  being determined by the duration of said logic level.  
     
     
         10 . A method of  claim 9  wherein the length of said descriptive information is determined by the trailing edge of said command signal logic level.  
     
     
         11 . An apparatus of  claim 1  wherein said local heterodyne frequency is maintained by a phase-locked loop subsequent to transmission from the apparatus of  claim 2  established by the command level of  claim 8 .  
     
     
         12 . An apparatus of  claim 1  wherein said local heterodyne frequency is maintained by a digitally controlled frequency synthesizer that receives its code from the apparatus of  claim 9 .  
     
     
         13 . A method of  claim 2  wherein any apparatus of  claim 1  may be frequency locked to any representative apparatus of  claim 2  once said apparatus is transmitting.  
     
     
         14 . The apparatus of  claim 1 , wherein said electronics are manufactured with surface-mount technologies using monolithic integrated, discrete-component circuits, effecting a micro-receiver suitable for miniature earphones.  
     
     
         15 . The apparatus of  claim 2 , wherein said audio source is contained within the apparatus of  claim 2  rather than being an auxiliary or external source.  
     
     
         16  The apparatus of  claim 15 , wherein said contained audio source is a microphone with associated level control components.  
     
     
         17 . The apparatus of  claim 2 , wherein said apparatus is incorporated into or contained within other electronics devices that provide source material for transmission.  
     
     
         18 . An apparatus of  claim 1 , wherein said electronics are digital in nature, making use of any of the common digital methods of demodulation and decoding as customary in spread-spectrum devices, said methods being any of time-division multiple access, code-division multiple access, or frequency-division multiple access.  
     
     
         19 . An apparatus of  claim 2 , wherein said electronics are digital in nature, making use of any of the common digital methods of modulation and encoding as customary in spread-spectrum devices, said methods being any of time-division multiple access, code-division multiple access, or frequency-division multiple access.  
     
     
         20 . The apparatus of  claim 1 , wherein said earphones are mounted externally to the ear and either attached to the ear by independent loop contrivances or attached together with said attachment wire or frame being worn over the head in the usual manner of earphones.  
     
     
         21 . An apparatus of  claim 1 , wherein said receiver unit presents its demodulated audio signal to a connector rather than to an acoustic transducer, making said audio signal available for use by other electro-acoustic devices.