Multi-channel digital transmitter and receiver

A filter comprising a plurality of pre-conditioning means for pre-conditioning a digitized signal for subsequent digital signal processing, each pre-conditioning means comprising:

• (a) an integrator;
• (b) a first and a second differencer, each operatively coupled to an output of the integrator, the second differencer being operatively coupled through a delay element;
• (c) a first and a second multiplier, operatively coupled to the first and the second differencer, respectively, for generating a scaled output of the first and the second differencer;
• and
• (d) a summing means, operatively coupled to the first and the second multiplier, for generating a portion of the pre-conditioned digitized signal from the scaled outputs of the first and the second multiplier.

A filter comprising a plurality of post-conditioning means for post-conditioning a digitized signal after digital signal processing, each post-conditioning means comprising:

• (a) a differencer;
• (b) an integrator operatively coupled to an output of the differencer;
• (c) a first and a second multiplier, operatively coupled to the integrator, for generating a scaled output of the integrator, the second multiplier being operatively coupled through a delay element;
• and
• (d) a summing means, operatively coupled to the first and the second multiplier, for generating a portion of the post-conditioned digitized signal from the scaled outputs of the first and the second multiplier.

A filter comprising a plurality of pre-conditioning means for pre-conditioning a digitized signal for subsequent digital signal processing, each pre-conditioning means comprising:

• (a) an integrator of at least order one;
• (b) a first, a second, and a third differencer, each operatively coupled to an output of the integrator, each of at least order one, the second differencer being operatively coupled through a delay element, the third differencer being operatively coupled through at least two delay elements;
• (c) a first, a second, and a third multiplier, operatively coupled to the first, the second, and the third differencer, respectively, for generating scaled outputs of each differencer, respectively;
• and
• (d) a summing means, operatively coupled to the each of the multipliers, for generating a portion of the pre-conditioned digitized signal from the scaled outputs of the multipliers.

A filter comprising a plurality of post-conditioning means for post-conditioning a digitized signal after digital signal processing, each post-conditioning means comprising:

• (a) a differencer of at least order one;
• (b) an integrator of at least order one operatively coupled to an output of the differencer;
• (c) a first, a second, and a third multiplier, operatively coupled to the integrator, for generating scaled outputs of the integrator, the second multiplier being operatively coupled through a delay element, the third multiplier being operatively coupled through at least two delay elements;
• and
• (d) a summing means, operatively coupled to each of the multipliers, for generating a portion of the post-conditioned digitized signal from the scaled outputs of the multipliers.

A communication receiving unit, comprising:

• (a) input means for intercepting electromagnetic radiation within a frequency band;
• (b) digitizing means, coupled to the input means, for digitizing a portion of the intercepted electromagnetic radiation into a digitized signal;
• (c) a plurality of filtering means, coupled to the digitizing means, for pre-conditioning the digitized signal for subsequent Fourier transformation, each filtering means comprising:
• (i) an Nth order integrator;
• (ii) a first, a second, and a third Nth order differencer, each coupled to an output of the integrator, the second differencer being coupled through a first delay element, and the third differencer being coupled through the first and a second delay element;
• (iii) a first, a second, and a third multiplier, coupled to the first, the second, and the third differencer, respectively, for generating scaled outputs of each differencer, respectively;
• and
• (iv) summing means, coupled to the each of the multipliers, for generating a portion of the pre-conditioned digitized signal from the scaled outputs of the multipliers;
• (d) Fourier transforming means, coupled to the plurality of filtering means, for generating a digitized channel signal from the pre-conditioned portions of the digitized signal;
• (e) conditioning means, coupled to the Fourier transforming means, for removing undesired signals from the digitized channel signal;
• and
• (f) detecting means, coupled to the conditioning means, for detecting an information signal within the digitized channel signal.

A communication transmitting unit, comprising:

• (a) input means for receiving a plurality of digitized information signals to be transmitted;
• (b) conditioning means, coupled to the input means, for removing undesired signals from the plurality of digitized information signals;
• (c) inverse Fourier transforming means, coupled to the conditioning means, for generating a plurality of digitized signals from the plurality of digitized information signals;
• (d) a plurality of filtering means, coupled to the inverse Fourier transforming means, for post-conditioning the plurality of digitized signals for subsequent transmission, each filtering means comprising:
• (i) an Nth order differencer;
• (ii) an Nth order integrator coupled to an output of the differencer;
• (iii) a first, a second, and a third multiplier, coupled to the integrator, for generating scaled outputs of the integrator, the second multiplier being coupled through a first delay element, and the third multiplier being coupled through the first and a second delay element;
• and
• (iv) summing means, coupled to each of the multipliers, for generating a portion of the post-conditioned digitized signal from the scaled outputs of the multipliers;
• (e) conversion means, coupled to the plurality of filtering means, for generating a composite analog transmission signal from the portion of the post-conditioned digitized signal of each filtering means;
• and
• (f) frequency selection means, coupled to the conversion means, for selecting a communication channel to transmit the composite analog transmission signal.

A method for processing a digitized signal, comprising the steps of:

• (a) integrating portions of the digitized signal into an integrated signal;
• (b) taking a difference of the integrated signal;
• (c) multiplying the differenced integrated signal;
• and
• (d) generating a digitized channel signal by Fourier transforming the multiplied integrated signal.

A method for processing a plurality of digitized information signals, comprising the steps of:

• (a) generating a composite digitized channel signal by inverse Fourier transforming the plurality of digitized information signals;
• (b) taking a difference of the composite digitized channel signal;
• (c) integrating the differenced composite digitized channel signal into an integrated signal;
• and
• (d) multiplying the integrated signal, by a scaling factor.

A communication receiving unit, comprising:

• (a) an analog-to-digital conversion means for digitizing a selected portion of an input frequency band;
• (b) commutating means, operatively coupled to the analog-to-digital conversion means, for subdividing the digitized portion of the input frequency band into the plurality of digitized signal portions;
• (c) discrete Fourier transforming means, operatively coupled to the commutating means, for generating a plurality of digitized channel signals by discrete Fourier transforming the plurality of digitized signal portions, the discrete Fourier transforming means comprising conditioning means for pre-conditioning the plurality of digitized signal portions with a modified cascaded integrator comb filter;
• and
• (d) a detecting means, operatively coupled to the discrete Fourier transforming means, for detecting at least two information signals from the plurality of digitized channel signals.

A communication transmitting unit, comprising:

• (a) inverse discrete Fourier transforming means for generating a plurality of digitized signals by inverse discrete Fourier transforming a plurality of input digitized information signals, the inverse discrete Fourier transforming means comprising conditioning means for post-conditioning the plurality of digitized signals with a modified cascaded integrator comb filter;
• (b) commutating means, operatively coupled to the inverse discrete Fourier transforming means, for combining portions of the plurality of digitized signals into a composite digitized signal;
• (c) digital-to-analog conversion means, operatively coupled to the commutating means, for generating a composite analog transmission signal from the composite digitized signal;
• and
• (d) transmitting means, operatively coupled to the digital-to-analog conversion means, for transmitting the composite analog transmission signal over a frequency band.