Apparatus, methods and articles of manufacture for pre-emphasis filtering of a modulated signal

1. A method of determining a transfer function used for emphasizing a portion of an electromagnetic signal prior to being processed in a processing system comprising the steps of:

determining a discrete transfer function for said processing system;

determining a target transfer function such that said target transfer function multiplied by the inverse of said discrete transfer function produces a discrete pre-emphasis transfer function; and

transforming any unstable poles and/or zeros in said pre-emphasis transfer function to stable poles and/or zeros;

wherein said target transfer function represents a low pass FIR filter having a gain of about unity across substantially all of the frequency range of said FIR filter.

2. The method of claim 1 , wherein said discrete transfer function is determined using one of an S-function, input and output signals, inverse-invariant method, or Steiglitz-McBride algorithm.

3. The method of claim 1 , wherein said transformation of said unstable poles and/or zeros is accomplished using an all pass filter.

4. The method of claim 1 , wherein said processing system comprises one of phase modulation, or wideband phase modulation, wideband fractional sigma delta modulation, or wideband fractional sigma delta modulation for a code division multiple access signal.

5. A method for electromagnetic processing of an input wave, wherein an input signal containing a characteristic of said input wave is processed to produce a modified signal, said method comprising the steps of:

receiving said input signal containing said characteristic of said input wave;

transforming said input signal using a pre-emphasis transfer function based upon determining a discrete transfer function for said processing of said input signal, determining a target transfer function such that said target transfer function multiplied by the inverse of said discrete transfer function produces said pre-emphasis transfer function, and transforming any unstable poles and/or zeros in said pre-emphasis transfer function to stable poles and/or zeros, wherein said target transfer function represents a low pass FIR filter having a gain of about unity across substantially all of the frequency range of said FIR filter;

processing said transformed input signal to generate said modified signal; and

regulating said modified signal using a control signal containing another characteristic of said input wave to produce an output signal.

6. The method of claim 5 , wherein said discrete transfer function is determined using one of an S-function, input and output signals, inverse-invariant method, Steiglitz-McBride algorithm.

7. The method of claim 5 , wherein said transformation of said unstable poles and/or zeros is accomplished using an all pass filter.

8. The method of claim 5 , wherein said modified signal is a phase modulated signal and said processing involves one of phase modulation, wideband phase modulation, wideband fractional sigma delta modulation, or wideband fractional sigma delta modulation for a code division multiple access signal.

9. The method of claim 5 , wherein said characteristic used to regulate said modified signal is magnitude.

10. The method of claim 5 , wherein said step of regulating said modified signal is performed using a plurality of segments.

11. The method of claim 10 , wherein one or more of said segments is independently controlled as a power amplifier by a portion of two or more signals that represent said input wave to contribute power to said output signal.

12. The method of claim 11 , further comprising the step of generating said output signal by combining power outputted from one or more of said segments.

13. The method of claim 12 , wherein said step of generating said output signal by combining power is accomplished using one of power transformers, quarter-wave transmission lines, or discrete LC components.

14. The method of claim 10 , wherein one or more of said segments is independently controlled as a current source by a portion of two or more signals that represent said input wave to contribute current to said output signal.

15. A method of determining a transfer function used for emphasizing a phase signal from an input wave prior to being modulated in a phase modulator, said method comprising the steps of:

determining a discrete transfer function for said phase modulator;

determining a target transfer function such that said target transfer function multiplied by the inverse of said discrete transfer function produces a discrete pre-emphasis transfer function; and

transforming any unstable poles and/or zeros in said pre-emphasis transfer function to stable poles and/or zeros;

wherein said target transfer function represents a low pass FIR filter having a gain of about unity across substantially all of the frequency range of said FIR filter.

16. The method of claim 15 , wherein said discrete transfer function is determined using one of an S-function, input and output signals, inverse-invariant method, or Steiglitz-McBride algorithm.

17. The method of claim 15 , wherein said transformation of said unstable poles and/or zeros is accomplished using an all pass filter.

18. An apparatus for electromagnetic processing of an input wave, wherein an input signal containing a characteristic of said input wave is processed in a processing circuit to produce a modified signal, said apparatus comprising:

a filter for receiving said input signal containing said characteristic of said input wave; and transforming said input signal using a pre-emphasis transfer function based upon determining a discrete transfer function for said processing of said input signal, determining a target transfer function such that said target transfer function multiplied by the inverse of said discrete transfer function produces said pre-emphasis transfer function, and transforming any unstable poles and/or zeros in said pre-emphasis transfer function to stable poles and/or zeros, wherein said target transfer fUnction represents a low pass FIR filter having a gain of about unity across substantially all of the frequency range of said FIR filter;

a processing circuit for processing said input signal after said transformation in said filter to generate said modified signal; and

an output circuit for regulating said modified signal using a control signal containing another characteristic of said input wave to produce an output signal.

19. The apparatus of claim 18 , wherein said discrete transfer function is determined using one of an S-function, input and output signals, inverse-invariant method, or Steiglitz-McBride algorithm.

20. The apparatus of claim 18 , wherein said transformation of said unstable poles and/or zeros is accomplished using an all pass filter.

21. The apparatus of claim 18 , wherein said modified signal is a phase modulated signal and said processing circuit is one of a phase locked loop, a phase modulator, a wideband phase modulator, a wideband fractional sigma delta modulator, or a wideband fractional sigma delta modulator for a code division multiple access signal.

22. The apparatus of claim 18 , wherein said characteristic used to regulate said modified signal is magnitude.

23. The apparatus of claim 18 , wherein said output circuit is an amplifier comprising a plurality of segments.

24. The apparatus of claim 23 , wherein one or more of said segments is independently controlled as a power amplifier by said control signal to contribute power to said output signal, wherein said output circuit further comprises a combining circuit for combining the output from each of said segments to generate said output signal, and wherein said combining circuit comprises one of power transformers, quarter-wave transmission lines, or discrete LC components.

25. The apparatus of claim 23 , wherein one or more of said segments is independently controlled as a current source by a portion of two or more signals that represent said input wave to contribute current to said output signal.

26. A signal transmitter comprising:

a baseband processor for receiving an input wave and generating a magnitude signal and a phase signal representing said input wave;

a phase modulator for phase modulating said phase signal, said phase modulator having a modulator transfer function associated therewith;

a filter for transforming said phase signal prior to being modulated in said phase modulator, said filter having a pre-emphasis transfer function based upon determining a discrete transfer function from said modulator transfer function, determining a target transfer function such that said target transfer function multiplied by the inverse of said discrete transfer function produces said pre-emphasis transfer function, and transforming any unstable poles and/or zeros in said pre-emphasis transfer function to stable poles and/or zeros, wherein said target transfer function represents a low pass FIR filter having a gain of about unity across substantially all of the frequency range of said FIR filter; and

an amplifier comprising a plurality of segments for amplifying said phase modulated signal transformed by said filter using said magnitude signal to generate an output signal for transmission.

27. The transmitter of claim 26 , wherein said discrete transfer function is determined using one of an S-function, input and output signals, inverse-invariant method, or Steiglitz-McBride algorithm.

28. The transmifter of claim 26 , wherein said transformation of said unstable poles and/or zeros is accomplished using an all pass filter.

29. The transmitter of claim 26 futher comprising a combining circuit for combining the output from each of said segments to generate said output signal, wherein said combining circuit comprises one of power transformers, quarter-wave transmission lines, or discrete LC components.

30. The apparatus of claim 26 , wherein one or more of said segments is independently controlled as a current source by a portion of two or more signals that represent said input wave to contribute current to said output signal.