An asynchronous spread spectrum wireless-modem using a SAW convolver

Author

Tsubouchi, K. ; Tomioka, T. ; Sato, T. ; Endo, C. ; Mikoshiba, N.

Author_Institution

Res. Inst. of Electr. Commun., Tohoku Univ., Sendai, Japan

fYear

1988

fDate

2-5 Oct 1988

Firstpage

213

Abstract

The authors have developed a compact spread-spectrum (SS) wireless modem using a SAW (surface acoustic wave) convolver (the efficient ZnO-SiO₂-Si Sezawa wave convolver). The SS modem was based on a DS (data-scanning) method, where the PN (pseudonoise) code length was 127 bits and the code rate was 14 MHz. The demodulation method of the SS modem was a completely asynchronous one, which was very useful for application to wireless communication under the very weak signals. From 1989 in Japan, the allowed electric field of a transmitter without a license will be less than 500 μV/m at 3 m in the frequency range less than 322 MHz. Under this restriction the usual narrowband FM modem was effective only within a distance less than 11 m. The SS modem proved to be reliable for distances as far as 110 m

Keywords

modems; noise; radio equipment; spread spectrum communication; surface acoustic wave devices; 110 m; SAW convolver; ZnO-SiO₂-Si; asynchronous spread spectrum wireless-modem; code length; demodulation; electric field; narrowband FM modem; pseudonoise; transmitter; Acoustic waves; Convolvers; Demodulation; Frequency; Licenses; Modems; Spread spectrum communication; Surface acoustic waves; Transmitters; Wireless communication;

fLanguage

English

Publisher

ieee

Conference_Titel

Ultrasonics Symposium, 1988. Proceedings., IEEE 1988

Conference_Location

Chicago, IL

Type

conf

DOI

10.1109/ULTSYM.1988.49370

Filename

49370