16.一個正弦信號的周期是1ms，那么它的頻率是

A.2kHz                                                             B.1kHz

C.0.5kHz                                                          D.100Hz

17.根據(jù)噪聲的性質(zhì)，噪聲可分為脈沖噪聲、起伏噪聲和

A.多頻噪聲                                                      B.單頻噪聲

C.交調(diào)噪聲                                                      D.系統(tǒng)噪聲

18.語音信號的數(shù)字化過程稱為

A.語音編碼                                                      B.數(shù)字抽樣

C.語音壓縮                                                      D.語音量化

19.二進制碼具有抗干擾能力強、易于產(chǎn)生等優(yōu)點,下列采用二進制碼的技術是

A.PSM                                                             B.PCM

C.POM                                                            D.PAM

20.對于語音、圖像等隨機信號，量化誤差也是隨機的，它像噪聲一樣影響通信質(zhì)量，因此又稱為

A.量化噪聲                                                      B.量化誤碼

C.隨機誤碼                                                      D.編碼噪聲

21.VSAT衛(wèi)星網(wǎng)中，外向傳輸是指主站在外向信道上發(fā)送信號，小站

A.轉(zhuǎn)接外向信號                                               B.發(fā)送外向信號

C.檢測外向信號                                               D.接收外向信號

22.衛(wèi)星通信過程中采用的使轉(zhuǎn)發(fā)器容量提高2.5～4倍的技術叫做

A.效率利用                                                      B.功率激活

C.電平抑制                                                      D.話音激活

23.數(shù)字微波通信系統(tǒng)的容量是指每一射頻波道傳輸?shù)?/P>

A.標稱比特率                                                  B.標稱波特率

C.標稱波道數(shù)                                                  D.標稱基帶數(shù)

24.同步復接過程中，復接的各支路數(shù)據(jù)碼流時鐘出于同一個

A.主振蕩源                                                      B.脈沖源

C.信號源                                                         D.主電源

25.在目前的數(shù)字微波通信設備中，根據(jù)發(fā)信機頻率變換的方式不同，可分為直接調(diào)制式發(fā)信機和

A.間接調(diào)制式發(fā)信機                                        B.復合調(diào)制式發(fā)信機

C.變頻式發(fā)信機                                               D.外差式發(fā)信機