DIGITAL FREQUENCY MODULATING COMMUNICATION SYSTEM

摘要

PURPOSE:To prevent the lowering of the error rate of identification due to the intercode interference and the noise, by giving the frequency modulation to the digital information signal after the sum logic conversion at the transmission side and then giving the comparison and decoding to several cosine phases having different delay times at the reception side respectively. CONSTITUTION:Sum logic conversions 15 and 26 are given to digital information signal 13 at transmission side 11. Then frequency modulation 22 is given to the carrier wave by sum logic conversion output 23, and frequency modulation output 24 is transmitted. At reception side 26, received signal 28 is turned into two signals 38 and 39 or more with the delay by different times from each other. And then cosine phase comparisons 32 and 33 are given between delay signals 38/39 and signal 28, and cosine phase comparison outputs 47 and 48 are compounded 49 with the same phase. Then the transmission digital information signal is demodulated 52 based on the change of the phase state of composite signal 51.