公开(公告)号：US3605019A

公开(公告)日：1971-09-14

申请号：US3605019D

申请日：1969-01-15

Applicant: IBM

Inventor： CUTTER JOSEPH T ,  DAVIES JOHN M ,  FREEMAN DON G ,  SCHWARZ GORDON R ,  VANBLERKOM RICHARD

IPC: H04B7/04 ,  H04B15/00

CPC classification number: H04B7/04

Abstract: The invention is a communication system which causes errors introduced by selective frequency fading channels to be time localized. It does this by transmitting the Fourier transform of the baseband signal. The preferred embodiment consists of a frequency division multiplexor multiplexing a plurality of channels and a Fourier transformer taking the Fourier transform of the digital representation of the resultant waveform. The Fourier transform is reconverted into an analog representation by a D-A converter and transmitted by means of an A-D converter. The receiver reconverts the analog representation of the Fourier transform into a digital signal, a Fourier transformer takes the inverse transform, as a D-A converter, reconverts the digital representation back into an analog waveform and then an FDM demodulator demultiplexes the analog waveform resulting in a signal representative of the input to the transmitter with errors introduced by the channels appearing as burst errors (time localized).