A: The signal given
B: After the signal was given
C: Given the signal
D: A and B
举一反三
- _____, the train started. A: The signal given B: Giving the signal C: The signal being given D: The signal giving
- A ________may be given ____means of flags, lights, and guns. A: sign; by B: signal; in C: signal; by D: sign; in
- For a given signal constellation, the average probability of symbol error incurred in maximum likelihood signal detection over an AWGN channel is invariant to the _________________ of the signal constellation. A: compression B: translation C: expansion D: rotation
- Given the waveform of a signal below, the signal can be represented by ( )[img=447x268]180337892037599.png[/img] A: [img=99x39]180337892a0bca3.png[/img] B: [img=130x39]1803378932b78f3.png[/img] C: [img=130x39]18033789411cf20.png[/img] D: [img=161x39]180337894e2e7ba.png[/img]
- Given the spectrum [img=21x22]18033774ad81d04.png[/img] of a continuous-time signal is shown below, then, the periodic signal signal [img=50x25]18033774b570388.png[/img][img=295x129]18033774bfda33c.png[/img] A: [img=142x20]18033774c806bc3.png[/img] B: [img=133x20]18033774d008a32.png[/img] C: [img=199x25]18033774d8e0526.png[/img] D: [img=138x21]18033774e1e1bd2.png[/img]
内容
- 0
Given a voice signal [img=31x25]1803377a105a2ae.png[/img],if we transform the signal to a new signal [img=108x25]1803377a1936ebf.png[/img], what will the new signal [img=30x25]1803377a217e8d9.png[/img] be different from the original signal [img=31x25]1803377a2928967.png[/img]? A: The length of [img=30x25]1803377a3149b0c.png[/img] will be extended, and the pitch will be higher. B: The length of [img=30x25]1803377a3149b0c.png[/img] will be extended, and the pitch will be lower. C: The length of [img=30x25]1803377a3149b0c.png[/img] will be compressed, and the pitch will be higher. D: The length of [img=30x25]1803377a3149b0c.png[/img] will be compressed, and the pitch will be lower.
- 1
Given [img=214x47]18033783c242984.png[/img], then the initia value of the signal in the time domain, [img=44x26]18033783cb70806.png[/img] is ( ) A: 1 B: 1/2 C: 1/4 D: 2
- 2
a fixed signal that lets engineers know if a train can enter a block. A: ABS (automatic block system) B: lock C: lock signal
- 3
what is an analog signal? A: Analog signal is a continous values B: Analog signal is a discrete values C: Analog signal is sometimes continous,sometimes discrete
- 4
According to the meaning of stop signal, it is divided into absolute signal and （ ）. A: clea B: permissive signal C: estricting D: approach