CAJ | 학술논문

认知无线电可以利用本地未被使用的频谱, 在保证主系统用户服务前提下, 需要合理设置发射功率.为了量化信号传输路径中的不确定阴影, 使用对数正态分布路径损耗模型, 把发射功率和路径损耗中的不确定因素对应起来.由于路径损耗变化范围可能很大, 发射功率需要保留很大余量, 以确保对主系统的有害干扰在一定范围内.通过多用户协作方式, 相对单用户模式, 可以额外获得2 dB的发射功率.
인지무선전가이이용본지미피사용적빈보, 재보증주계통용호복무전제하, 수요합리설치발사공솔.위료양화신호전수로경중적불학정음영, 사용대수정태분포로경손모모형, 파발사공솔화로경손모중적불학정인소대응기래.유우로경손모변화범위가능흔대, 발사공솔수요보류흔대여량, 이학보대주계통적유해간우재일정범위내.통과다용호협작방식, 상대단용호모식, 가이액외획득2 dB적발사공솔.
Cognitive radio can reuse locally unused spectrum for their own transmission. It is proved that a cogni-tive radio can vary its transmit power while maintaining a guarantee of service to primary users. Using a log-normal path loss model and find quantitative bounds on the transmion power to account for uncertainty while retaining the necessary performance metric. The shadowing provides a very large dynamic range in possible path losses, and so the margin required to guarantee any sort of harmful interference bound must be large. By using cooperation, this bound could be reduced, cooperation can recovers 2dB from the single user case.