PHASE NOISE REMOVING CIRCUIT OF RECEIVER, FEEDFORWARD CIRCUIT, FEEDFORWARD SPECTRAL DIFFUSION SIGNAL PROCESSOR AND SPECTRAL DIFFUSION COMMUNICATION SYSTEM

摘要

PURPOSE: To improve total system performance by providing a detector means to respond to a spread spectrum signal and a subtracting means connected to the detector means for responding to the spread spectrum signal and to respond to a pilot carrier and perform communication in a low S/N. CONSTITUTION: A signal supplied to an input of a signal processor part of a receiver 10 appears in an input terminal 11 of a first mixer 12. The input signal is a 70MHz intermediate frequency(IF) signal. The first mixer 12 mixes the 70MHz IF signal with a 22MHz reference signal, to convert a signal into a band of 44 to 52MHz. The signal is sampled to a first A/D converter 14 with twice that of a chip ratio after it is filtered by 44 to 52MHz in a first band-pass filter 13. And synchronization signal whose phase noise is removed is multiplexed by a spread spectrum sequence from a data sequence generator 22 in a second mixer 15.