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(jìn)制碼具有抗干擾能力強(qiáng)、易于產(chǎn)生等優(yōu)點,下列采用二進(jìn)制碼的技術(shù)是

A.PSM                                                             B.PCM

C.POM                                                            D.PAM

20.對于語音、圖像等隨機(jī)信號，量化誤差也是隨機(jī)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(jī)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(shù)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(biāo)稱比特率                                                  B.標(biāo)稱波特率

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

24.同步復(fù)接過程中，復(fù)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(shè)備中，根據(jù)發(fā)信機(jī)頻率變換的方式不同，可分為直接調(diào)制式發(fā)信機(jī)和

A.間接調(diào)制式發(fā)信機(jī)                                        B.復(fù)合調(diào)制式發(fā)信機(jī)

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