Method for modulating a carrier signal and method for demodulating a modulated carrier signal

Abstract

A method for modulating a carrier signal used for transmitting analog or digital message signals is provided. The module k of elliptic functions is used as a modulation parameter instead of the amplitude or the frequency. The carrier signal modulated according to this modulation method is provided with a constant amplitude and a fixed frequency while the signal form is chronologically modified at the rhythm of the message that is to be transmitted.

1 - 18 . (canceled) 
   
   
       19 . A method for modulating a carrier signal for the transmission of message signals, comprising:
 varying a signal shape of the carrier signal over time by a message signal to be transmitted, an amplitude and a frequency of the carrier signal remaining constant.   
   
   
       20 . The method as recited in  claim 19 , wherein a time characteristic of the carrier signal is defined by an elliptic function. 
   
   
       21 . The method as recited in  claim 20 , wherein the elliptic function is a Jacobian elliptic function. 
   
   
       22 . The method as recited in  claim 20 , wherein modulus k of the elliptic function is varied over time by the message signal to be transmitted so as to modulate the signal shape of the carrier signal in a rhythm of the message signal to be transmitted. 
   
   
       23 . The method as recited in  claim 20 , wherein the time characteristic of the modulated carrier signal is defined by the elliptic function s(t)=a 0  sx(2{circumflex over (π)}f 0 t,k(t)), a 0  being the amplitude and f 0  the frequency, and {circumflex over (π)} and modulus k being linked via a complete elliptic integral of a first kind. 
   
   
       24 . The method as recited in  claim 23 , wherein the function sx(2{circumflex over (π)}f 0 t,k(t)) for 0≦k(t)≦1 is defined by Jacobian elliptic function sn(2{circumflex over (π)}f 0 t,k(t)), and for −1≦k(t)≦0 by Jacobian elliptic function cn(2{circumflex over (π)}f 0 (t−T/4),k(t)). 
   
   
       25 . The method as recited in  claim 20 , wherein an orthogonal transmission method is used, which is based on orthogonal elliptic basic functions (sn(2{circumflex over (π)}f 0 t,k(t)), sd(2{circumflex over (π)}f 0 t,k(t)), cd(2{circumflex over (π)}f 0 t,k(t)) and cn(2{circumflex over (π)}f 0 t,k(t))). 
   
   
       26 . The method as recited in  claim 20 , wherein the carrier signal defined by the elliptic function is generated using an analog circuit configuration which supplies at least one modulated carrier signal (s(t)) whose curve shape at least one of sectionally corresponds to and is approximated to an elliptic function. 
   
   
       27 . An apparatus for modulating a carrier signal for the transmission of message signals, comprising:
 a modulator, wherein the modulation by the modulator of the carrier signal (s(t)) is implemented so that a signal shape of the carrier signal is able to be varied over time by a message signal (m(t)) to be transmitted, the amplitude (a 0 ) and the frequency (f 0 ) of the carrier signal (s(t)) remaining constant.