It is first time to adopt the high-speed frequencyspread microwave network for China Seismological Bureau.
采用扩频微波方式组网在地震系统还尚属首次。
2
Ocean underwater channel is a stochastic acoustic propagation channel with its multipaths, time variety, and frequencyspread.
海洋水声信道是多途、时变和频散的信道。
3
The CDMA based on the radio frequencyspread technique has been a very attractive multiple access technique in the radio communication field since 1990.