基帶
基帶(英語:baseband)是頻率範圍非常窄的訊號,也就是說振幅譜僅在原點(f = 0)附近才是非零的,其他頻率幾乎可以忽略。[1] 在電信與訊號處理中,基帶訊號是未經載波調制的訊號,即該訊號的頻率範圍沒有任何移位,[2] 而且頻率很低 - 包含頻帶從接近 0 Hz到更高截止頻率或最大頻寬。
![](http://upload.wikimedia.org/wikipedia/commons/thumb/9/92/Bandlimited2.svg/300px-Bandlimited2.svg.png)
由於基帶訊號是未經載波調制的訊號,在GPS接收機和流動電話等無線數碼通訊領域,基帶訊號有時也泛指已經過射頻前端處理後的訊號。[3][4]在無線通訊裝置中,來自天線的訊號先經射頻前端的模擬電路接收,然後再轉交給後續的數碼電路進一步處理,而後者就是基帶處理器。[3][4]在當前中文語境中,手機基帶處理器所帶的韌體也簡稱「基帶」[5]。
參見
編輯參考文獻
編輯- ^ Leon W. Couch II. Digital and Analog Communication Systems. Prentice Hall. 1993.
- ^ B.P. Lathi. Modern Digital and Analog Communication Systems. Holt, Rinehart and Winston. 1983.
- ^ 3.0 3.1 Christian Piguet. 6: Low-Power Bandband Processors for Communications. Low-Power Processors and Systems on Chips. CRC Press. [2020-01-10]. (原始內容存檔於2020-04-26).
Baseband Signals are all signals in a radio system, which are not modulated onto the carrier wave. In a cellular phone, this means all signals except those in the radio frequency (RF) part of the phone.
- ^ 4.0 4.1 U.S. International Trade Commission. In the Matter of Certain GPS Chips, Associated Software and Systems, and Products Containing Same, Investigation No. 337-TA-596 (報告). DIANE Publishing: 6.
A GPS receiver typically includes an analog signal processing portion in a radio-frequency circuit (an "RF Front End") and a digital signal processing portion in a baseband circuit (a "Baseband Processor"). In a GPS receiver, the RF Front End receivers the GPS signal, filters and amplifies the signal, and converts the resulting signal into a digital formbat. The resulting digital signal, which is sometimes referred to as the "baseband signal," is sent to the Baseband Processor.
- ^ 基带是什么. 太平洋IT百科. [2016-02-07]. (原始內容存檔於2016-02-07).