Circuit and method for compensating for nonlinear distortion of input signal

A circuit for compensating for intermodulation distortion of an input signal, said input signal including a plurality of major signals, each having a corresponding predetermined frequency, said circuit comprising:

• a spectrum analyzer for analyzing said input signal and detecting said plurality of major signals and generating a detected major frequencies signal representing each of said predetermined frequencies;
• a distortion frequency calculator for calculating a plurality of distortion frequency signals based on said detected major frequencies signal and a plurality of predetermined formulae representing secondary and tertiary intermodulation distortion;
• a branching circuit for branching said input signal into a first signal and a second signal;
• an extractor, responsive to said distortion frequency signals, for extracting frequency components from said first signal received from said branching circuit, said frequency components having said distortion frequencies;
• and
• an eliminator for eliminating a signal having said distortion frequency from said second signal based on said extracted frequency components.

A circuit for compensating for harmonic distortion of an input signal, said input signal including a plurality of major signals, each having a predetermined frequency, said circuit comprising:

• a spectrum analyzer for analyzing said input signal and detecting said plurality of major signals and generating a detected major frequencies signal representing said predetermined frequencies;
• a distortion frequency calculator for calculating a plurality of distortion frequency signals based on said detected major frequencies signal and at least one predetermined formula representing said harmonic distortion;
• a branching circuit for branching said input signal into a first signal and a second signal;
• an extractor, responsive to said distortion frequency signals, for extracting frequency components having from said first signal received from said branching circuit, said frequency components having said distortion frequencies;
• and
• an eliminator for eliminating a signal having said distortion frequency from said second signal based on said extracted frequency components.

A transmission system comprising:

• a power amplifier for amplifying a power of an input signal to generate an amplified input signal, said input signal including a plurality of major signals, each having a respective predetermined frequency;
• a spectrum analyzer for analyzing said amplified input signal and detecting said plurality of major signals and generating a detected major frequencies signal representing said predetermined frequencies;
• a distortion frequency calculator for calculating a plurality of distortion frequency signals based on said detected major frequencies signal and a plurality of predetermined formulae representing said nonlinear distortion;
• a branching circuit for branching said amplified input signal into a first signal and a second signal;
• an extractor, responsive to said distortion frequency signals, for extracting frequency components having from said first signal received from said branching circuit, said frequency components having said distortion frequencies, respectively;
• and
• an eliminator for eliminating a signal having said distortion frequency from said second signal based on said extracted frequency components.

A method for compensating for non-linear distortion of an input signal, said input signal including a major signal having a predetermined frequency, said method comprising steps of:

• spectrum analyzing said input signal to detect said major signal and generating a detected major frequency signal representing said predetermined frequency;
• calculating a distortion frequency relative to said predetermined frequency based on said detected major frequency signal and a predetermined formula representing said nonlinear distortion;
• branching said input signal into a first signal and a second signal;
• extracting a frequency component having said distortion frequency from said first signal in response to said detected major frequency signal;
• and
• eliminating a signal having said distortion frequency from said second signal based on said extracted frequency component.

A method for compensating for intermodulation distortion of an input signal, said input signal including a plurality of major signals, each having a respective predetermined frequency, said method comprising steps of:

• spectrum analyzing said input signal to detect said plurality of major signals and generating a detected major frequencies signal representing each of said predetermined frequencies;
• calculating a plurality of distortion frequencies from said predetermined frequencies based on said detected major frequencies signal and a plurality of predetermined formulae representing secondary and tertiary intermodulation distortions;
• branching said input signal into a first signal and a second signal;
• extracting frequency components from said first signal in response to said calculated distortion frequencies, said frequency components having said distortion frequencies;
• and
• eliminating a signal having said distortion frequencies from said second signal based on said extracted frequency components.

A method for compensating for harmonic distortion of an input signal, said input signal including a plurality of major signals, each having a respective predetermined frequency, said method comprising steps of:

• spectrum analyzing said input signal to detect said plurality of major signals and generating a detected major frequencies signal representing said predetermined frequencies;
• calculating a plurality of distortion frequencies based on said detected major frequencies signal and at least one predetermined formula representing said harmonic distortion;
• branching said input signal into a first signal and a second signal;
• extracting frequency components having from said first signal in response to said calculated distortion frequencies, said frequency components having said distortion frequencies;
• and
• eliminating a signal having said distortion frequency from said second signal based on said extracted frequency components.