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一、接收机 接收机负责接收GSM（全球数字蜂窝移动通信系统）发来的电磁波,基站发的信号有手机指令、话音。接收机将天线拾取的电磁波放大、解调、数字处理、信道解码、语音解码后通过耳机变成声音信号。图1给出V998机信号流程图。V998型是 GSM双频机,天线接收GSM、DCS频段时,天线开关U101选择频段。U101如
First, the receiver Receiver is responsible for receiving GSM (Global Digital Cellular Mobile Communication System) sent from the electromagnetic waves, the signal sent by the base station mobile phone commands, voice. The receiver picks up the electromagnetic wave picked up by the antenna to amplify, demodulate, digitally process, decode the channel, and decode the speech and then turn it into a sound signal through the earphone. Figure 1 shows the V998 machine signal flow chart. V998 is a GSM dual-band machine, the antenna receives GSM, DCS band, the antenna switch U101 select the band. U101 as