In management information system, the query performance of database has important effect on the application and spread of the system.
管理信息系统中，数据库的查询性能对系统的应用和推广具有重要的影响。
2
Simulation shows co-channel interference and maximum multi-path delay spread have significant impact on the BER performance and PDMRC gives the best performance in most common environment.
仿真表明同信道干扰与最大多径延迟扩展对系统性能影响很大，在通常情况下采用PDMRC具有最好的性能。
3
The performance of Direct Sequence Spread Spectrum(DSSS) in severe pulsed noise interference will be badly degraded when the duty factor is small.