单项选择题
A.106bits/s,2X106bit/s B.106bits/s,106bits/s C.2X106bit/s,106bits/s D.2X106bit/s,2X106bit/s
A.连续谱 B.离散谱 C.连续谱和离散谱 D.直流
A.带宽变宽,信噪比提高 B.带宽变宽,信噪比降低 C.带宽变窄,信噪比提高 D.带宽变窄,信噪比降低