Method and apparatus for performing Nyquist folding frequency modulation

A method for re-modulating a radio frequency carrier modulated signal comprising:

• sampling an analog radio frequency carder modulated signal to form a digitized radio frequency carrier modulated signal having a carrier frequency of a first frequency;
• modulating the digitized radio frequency carrier modulated signal with a repeating sequence of {1,−1,1,−1, . . . } having a sample rate of a second frequency to produce a remodulated radio frequency carrier modulated signal whose center frequency is a third frequency, said second frequency being equal to four times the first frequency resulting in the third frequency being equal to the first frequency and a spectrum of the remodulated radio frequency carrier modulated signal being inverted;
• and
• re-inverting the spectrum of the remodulated radio frequency carrier modulated signal.

A method for re-modulating a radio frequency carrier modulated signal comprising:

• resampling a digital radio frequency carrier modulated signal to form a digitized radio frequency carrier modulated signal having a carrier frequency of a first frequency;
• modulating the digitized radio frequency carrier modulated signal with a repeating sequence of {1,−1,1,−1, . . . } having a sample rate of a second frequency to produce a remodulated radio frequency carrier modulated signal whose center frequency is a third frequency, said second frequency being equal to four times the first frequency resulting in the third frequency being equal to the first frequency and a spectrum of the remodulated radio frequency carrier modulated signal being inverted;
• and
• re-inverting the spectrum of the remodulated radio frequency carrier modulated signal.