What is the baseband of Android phone?

Baseband is a circuit in the mobile phone, which is responsible for demodulating, descrambling, despreading and decoding the wireless signals in the mobile network, and transmitting the finally decoded digital signals to the upper processing system for processing. [1] In our mobile phone, it usually consists of two parts, one is the high-level processing part, which is equivalent to the computer we use;

The other part is baseband, which is equivalent to the modem we use. What network standard does the mobile phone support (GSM, CDMA, WCDMA, TD-SCDMA, etc.)? ) is determined by it, just like the difference between ADSL modem and ordinary narrowband modem. When we use mobile phones to make phone calls, surf the Internet, send text messages, etc. We send instructions (usually standard AT instructions) to the baseband part through the upper processing system, and these instructions will be processed and executed by the baseband part. After the baseband part is processed, a logical channel will be established between the mobile phone and the wireless network, and our voice, SMS or Internet data packets will be sent out through this logical channel.

Baseband refresh;

With the development of software radio technology, the baseband part of mobile phones can basically decode wireless signals with software. At the same time, using software radio technology can easily upgrade the baseband part to meet different needs or correct bugs in the baseband part.