| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem of an influence upon communication when a direct spread (DS) system is used and if an interference wave has large power in a satellite communication system in which spread spectrum system is used in consideration of interference resistance, and also the problem of the occurrence of a missing data in a frequency hopping (FH) system because a signal in an interfered frequency band cannot be reproduced. <P>SOLUTION: In a DS-CDMA system provided with features in the DS and the FH systems and having a flat power level characteristic in a frequency band, the power level of each frequency can be detected at reception. By use thereof, whether or not an interference wave exists is determined by the comparison of the detected power level with a power level required for communication. By the deletion of a frequency band, determined to be an interference wave, before demodulation, an increased noise level at demodulation (inverse spread) is suppressed, to enable normal reception. At transmission, an influence of the interference wave can be removed by executing spreading in regard to a band excluding the interference frequency band. <P>COPYRIGHT: (C)2013,JPO&INPIT |
