FM modulation technique for producing frequency rejection bands

Claim 3

The method according to claim 1 , further comprising the step of: passing the summed frequency spectrum having the matching main null and noise to a filter for rejecting the noise on the summed frequency spectrum; wherein, since the noise is located at and matched by the main null, the summed noise-rejected frequency spectrum has an energy level approximately identical to the summed frequency spectrum before the noise rejection.

Claim 4

The method according to claim 2 , further comprising the step of: compressing the noise rejected frequency spectrum so as to transform the same into a compressed signal pulse having approximately the same energy level as the summed frequency spectrum before the noise rejection; whereby the compressed signal pulse has available signal power, to be received by a receive means, which has not been decreased by the filter.

Claim 5

The method according to claim 1 , wherein the transforming step comprises the step of: Fourier transforming each portion according to the formula sin  [ πΔ  ( f - f i ) ] πΔ  ( f - f i ) where f=frequency of the portion under consideration; Δ=width of the portion; f i =frequency at which the peak of the spectrum for the portion is located.

Claim 6

The method according to claim 4 , wherein the summation step comprises the step of: summing the respective Fourier transforms of the portions according to the formula ∑ i = 1 N  sin  [ πΔ  ( f - f i ) ] πΔ  ( f - f i ) where Σ=summation sign f=frequency of the portion under consideration Δ=width of the portion; f i =frequency at which the peak of the spectrum for the portion is located.

Claim 7

The method according to claim 1 , further comprising the step of: defining for the frequency spectrum of each portion a plurality of null positions according to the formula f null = f i ± n   π Δ where f null =null positions for the portion; f i =frequency at which the peak of the spectrum for the portion is located; Δ=width of the portion; and selecting for each frequency spectrum one of the plurality of the defined null positions for placement of the interest point.

Claim 8

In a system for receiving signal pulses some of which having interferences superposed thereon, a method of eliminating the interferences by producing at least one signal pulse having at least one null for cancelling each of the interferences, the method comprising the steps of: selecting a bandwidth for the signal pulse; the signal pulse having at least one interference superposed thereon; separating the bandwidth into a predetermined number of steps, each step having its own frequency; determining equal width values for the steps by dividing the bandwidth with the predetermined number; designating the location of the interference on the signal pulse as a point of interest; Fourier transforming the respective steps; summing the respective Fourier transforms of the steps such that a null for each of the transforms is coincident at the point of interest, the summed transforms producing a signal spectrum for the signal pulse having a main null at the point of interest, the main null matching the interference on the signal pulse.

Claim 9

In a system for receiving signal pulses some of which having interferences superposed thereon, a method of eliminating the interferences by producing at least one signal pulse having at least one null for cancelling each of the interferences, the method comprising the steps of: selecting a bandwidth for the signal pulse; the signal pulse having at least one interference superposed thereon; separating the bandwidth into a predetermined number of steps, each step having its own frequency; determining equal width values for the steps by dividing the bandwidth with the predetermined number; designating the location of the interference on the signal pulse as a point of interest; Fourier transforming the respective steps; summing the respective Fourier transforms of the steps such that a null for each of the transforms is coincident at the point of interest, the summed transforms producing a signal spectrum for the signal pulse having a main null at the point of interest, the main null matching the interference on the signal pulse.

Claim 10

The method according to claim 7 , further comprising the step of: passing the signal spectrum to a filter for filtering the interference on the signal spectrum at the point of interest; wherein, insofar as the interference is located at the main null, the filtered signal spectrum maintains an energy level unaffected by the filter.

Claim 11

The method according to claim 8 , further comprising the step of: compressing the filtered signal spectrum in order to form a corresponding compressed signal pulse for detection by a receiver means, the compressed signal having an amplitude corresponding to the energy level of the filtered signal spectrum.

Claim 12

The method according to claim 7 , wherein the Fourier transforming step comprises the step of: proportioning each respective step according to the equation sin  [ πΔ  ( f - f i ) ] πΔ  ( f - f i ) where f=frequency of the step Δ=width of the step; f i =frequency at which the peak of the spectrum for the portion is located.

Claim 13

The method according to claim 7 , further comprising the step of: defining for each Fourier transform of the steps a plurality of null position according to the equation f null = f i ± n   π Δ where f null =null positions for the Fourier transform of the step; f i =frequency at which the peak of the spectrum for the portion is located; Δ=width of the step; and selecting for each Fourier transform one of the plurality of the defined null positions for coincidental placement at the point of interest.