在CDMA系统中当两信号的多径时延相差大于一个()时,这两个信号是不相关的,或者说是可分离的。我们习惯上将某一可分离的信号叫做信号的()。
参考答案:扩频码片宽度;径
简述灌砂试验中应注意的问题。
—Could you tell me _______ to go to Hainan by air?
—Just a minute, please. I have to check my computer. [ ]
A. how much does it cost
B. how much did it cost
C. how much it cost
D. how much it costs