METHOD AND DEVICE FOR FILTERING INTERFERENCE AND NONLINEAR DISTORTION

摘要

PROBLEM TO BE SOLVED: To provide a robust and inexpensive system for eliminating nonlinear distortion in a transmission signal. SOLUTION: A media access controller(MAC) 12 controlled by a CPU 10 controls and matches various states of transmitted and received data. A transmission signal is transmitted from the MAC 12 to a QAM modulator 14, is next subjected to RF conversion by an up-converter 16 and transmitted through a two-way HFC(hybrid fiber/coaxial) network 22. In a signal received by a return path receiver 20, received noise is analyzed by an internal DSP(digital signal processing) and changes in an interference peak are transmitted from the receiver to a transmitter while the signal is parallely subjected to A/D conversion and demodulation. The transmitter preliminarily distorts the transmission signal so as to emphasize a signal size in accordance with the change. The receiver receiving such a signal eliminates interference by removing preliminary distortion and performing demodulation.