Title :
A convolver based spread spectrum data communication system
Author_Institution :
Abteilung fuer Angewandte Elektronik, Tech. Univ. Vienna, Austria
Abstract :
An experimental data transmission system was designed for the control of moving machinery in electromagnetically polluted buildings, especially steel mills. Its operation is reported. The direct sequence spread spectrum system employs two surface acoustic wave convolvers as matched filters for the binary phase shift keying (BPSK) RF modulation with nearly orthogonal PN codes. Coherence bandwidths in steel mills range between 1 MHz and more than 20 MHz. The chip rate of the spread spectrum signal is 48 MHz, providing inherent diversity and reducing the multipath fading. Analog matched filtering by means of the convolvers offers the same flexibility and correlation gain as digital matched filter systems. The author´s receiver is far less sensitive to narrowband or square-wave deterministic interference. Synchronization is fast and works without a preamble. A simple equal gain echo combiner is implemented
Keywords :
automatic gain control; correlation methods; data communication; diversity reception; echo suppression; fading; indoor radio; industrial control; land mobile radio; matched filters; multipath channels; phase shift keying; pseudonoise codes; radiofrequency interference; spread spectrum communication; steel industry; surface acoustic wave convolution; synchronisation; 1 to 20 MHz; BPSK; analogue matched filtering; binary phase shift keying; chip rate; control of moving machinery; correlation gain; data transmission system; deterministic interference; direct sequence spread spectrum system; diversity; electromagnetically polluted buildings; equal gain echo combiner; flexibility; multipath fading; nearly orthogonal PN codes; operation; steel mills; surface acoustic wave convolvers; Binary phase shift keying; Communication system control; Control systems; Convolvers; Data communication; Machinery; Matched filters; Milling machines; Spread spectrum communication; Steel;
Conference_Titel :
Vehicular Technology Conference, 1993., 43rd IEEE
Conference_Location :
Secaucus, NJ
Print_ISBN :
0-7803-1267-8
DOI :
10.1109/VETEC.1993.510940
