设有模拟信号f(t)=4 sin 2000πtV,仅对其分别进行AM编码和A律13折线编码。 (1)AM编码的量化台阶△=0.1V,求不过载时的编码器输出码速率。 (2)当PCM编码时,其最小量化级△=0.003125V,试求f(t)为最大值和f(t)=-1.2V时的编码器输出码组和码元速率。
在下图的单音调幅波中,已知Ac=16,分别求Am=Ac/2,Am=Ac/4,Am=Ac/8时的信号总功率。
A.FM(调频) 和WaveTable(波表)
B.FM(调频)和AM(调幅)
C.AM(调幅)和WaveTable(波表)
D.FM(调频)和功率放大
听力原文:M: Why, you have to ask your parents to pay your rent?
W: Well, I am unable to make ends meet.
Q: What do we know about the woman?
(14)
A.She is financially in trouble.
B.She can't help her parents out.
C.She is unable to manage her money.
D.She can't get her parents to pay her rent.