Apparatus and method for carrier state modulation

Abstract

A carrier state modulator system is described in which a stream of digital data bits is encoded by modulating the amplitude or phase of a carrier wave. A transmitter directly modulates the amplitude or phase of a selected number of cycles of the carrier in accordance with the state of each digital data bit. This method of direct generation of an amplitude or phase modulated carrier wave differs from mixing a phase amplitude baseband modulation onto a higher carrier frequency.

1 . A transmitter for transmitting one or more bits of digital data, comprising:
 an oscillator to generate a carrier frequency having a voltage amplitude;   a voltage modulator to modulate the voltage amplitude on the basis of the one or more bits of digital data and to output a carrier state modulated signal; and   a transmitter to transmit the carrier state modulated signal,   wherein the voltage modulator modulates a selected number of one or more cycles of the carrier frequency for each bit of the one or more bits of digital data.   
     
     
         2 . The transmitter of  claim 1 , wherein a first level of digital data causes the modulator to increase the carrier voltage amplitude to a level greater than for a second level of digital data. 
     
     
         3 . The transmitter of  claim 2 , wherein the second level of digital data causes the voltage modulator to decrease the carrier voltage amplitude. 
     
     
         4 . A transmitter for transmitting one or more bits of digital data, comprising:
 a first oscillator to generate a carrier frequency having a voltage amplitude;   a phase modulator to modulate a phase of the carrier frequency on the basis of the one or more bits of digital data and to output a carrier state modulated signal; and   a transmitter to transmit the carrier state modulated signal,   wherein the phase modulator modulates a selected number of one or more cycles of the carrier frequency for each bit of the one or more bits of digital data, and   wherein a first level of digital data causes the phase modulator to output the carrier state modulated signal in phase with the carrier frequency and a second level of digital data causes the phase modulator to output the carrier state modulated signal 180 degrees out-of-phase with the carrier frequency.   
     
     
         5 . The transmitter of  claim 4 , comprising:
 a second oscillator to generate the carrier frequency 180 degrees out-of-phase with the first oscillator,   wherein, when the digital data is the first level then the phase modulator selects the carrier frequency from the first oscillator and when the digital data is the second level then the phase modulator selects the carrier frequency from the second oscillator.   
     
     
         6 .- 13 . (canceled) 
     
     
         14 . A method of coding one or more bits of digital data, comprising:
 modulating a voltage amplitude at a carrier frequency on the basis of the one or more bits of digital data;   outputting a carrier state modulated signal,   wherein a selected number of one or more cycles of the carrier frequency are modulated in the modulating step for each bit of the one or more bits of digital data.   
     
     
         15 . The method of coding of  claim 14 , wherein a first level of digital data causes an increase in the voltage amplitude to a level greater than for a second level of digital data. 
     
     
         16 . The method of coding of  claim 15 , wherein the second level of digital data causes a decrease in the voltage amplitude. 
     
     
         17 . A method of coding one or more bits of digital data, comprising:
 modulating a phase of a carrier frequency on the basis of the one or more bits of digital data;   outputting a carrier state modulated signal,   wherein the modulating step includes modulating the phase of a selected number of one or more cycles of the carrier frequency for each bit of the one or more bits of digital data, and   wherein a first level of digital data causes outputting of the carrier state modulated signal in phase with the carrier frequency and a second level of digital data causes outputting of the carrier state modulated signal 180 degrees out-of-phase with the carrier frequency.   
     
     
         18 - 25 . (canceled)