Highly Reliable Information and Communication Networks.
Project/Area Number  06650410 
Research Category 
GrantinAid for Scientific Research (C).

Research Field 
情報通信工学

Research Institution  NAGOYA UNIVERSITY 
Principal Investigator 
IWADARE Yoshihiro Nagoya Univ.Inform.Engrg., Prof., 工学部, 教授 (00232687)

Project Fiscal Year 
1994 – 1995

Project Status 
Completed(Fiscal Year 1995)

Budget Amount *help 
¥2,000,000 (Direct Cost : ¥2,000,000)
Fiscal Year 1995 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1994 : ¥1,000,000 (Direct Cost : ¥1,000,000)

Keywords  SPREAD SPECTRUM / FREQ.OFFSET / Mary SS / CYCLIC H MATRIX / SELFCHECKING / 2DIM.M PLANE / HADAMARD CODE / LSI TEST / スペクトル拡散通信 / 搬送波周波数偏差 / M進直交通信方式 / 巡回性H行列 / 自己検査回路 / 2次元M平面 / アダマル符号 / LSIテスト / ハミング符号化 / 見逃し誤り / 二次元擬似ランダム平面 / 自己検査性設計 / 直行符号 / スペクトル拡散通信方式 / ネットワーク設計 
Research Abstract 
As for Spread Spectrum (SS) Communication Systems, Mary SS communication systems robust to carrier frequency offsets have been investigated. When there exist carrier frequency offsets, it is known that transimmted signal powers are decreased and sprious components appear at the receiving ends. In order to cope with these phenomina, it is required that the frequency spectrums after multiplication process at the receiver are 1) well spread, 2) have no peaks and 3) have low power desity spectrums. As orthogonal codes to realize these properties, cyclic H matrices, whose core matrices are made of M sequences are found to be adequate. Togehter with receivers designed for these codes, it is found that the total system is quite robust to carrier frequency offsets. The design of selfchecking checkers for Hadamard codes have also been investigated. Hadamard codes are known to be quite useful in communication systems, signal processings and so forth. However, selfchecking checker design for these codes have never been proposed. It is found that this design can be made by using the properties of difference sets when the degreee of Hadamard matrices are prime numbers of the form p=8m+3 Finally, in the study of LSI tests, it is very important to have test inputs with strong randomness properties. Various randomness properties of partial fractions cut out from 2 dimensional random plane (Mplane) have been investigated to have quite excellent properties, superior than the sequences obtained from 1dimensional M sequences.

Report
(4results)
Research Output
(15results)