Affiliation: | (1) Department of Communications Engineering, National Defense Academy, Hashirimizu 1-10-20, Yokosuka, 239-8686 Japan e-mail: mituru@pop02.odn.ne.jp Fax:+81-468-44-5911, JP;(2) Tayca Co. Osaka laboratory, Funnamati 1-3-47 Taisho-ku, Osaka, 551-0022 Japan, JP |