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1.概述远动装置发送的原始信息通常是一种直流脉冲信号,这些直流脉冲信号不仅包含直流分量,而且还包含很多不同频率的分量。它所占用的基本频带简称基带,传输基带信号的系统称为基带传输系统,而在大多数场合下,为了适于信道的传送或提高数据的传输质量,一般均先把基带信号(发送信息码)经过调制后再送往信道。但是,有时也不经过调制就直接传输基带信号。在这种情况下,仅适宜于短距离传输低速的基带信号。因此,基带传输实际上受到了距离和速度的限制。
1. Overview The original information sent by the telemanipulator is usually a direct current pulse signal that contains not only the direct current but also many components of different frequencies. The basic frequency band it occupies is referred to as baseband and the system for transmitting baseband signals is referred to as a baseband transmission system. In most cases, in order to adapt to the transmission of channels or to improve the transmission quality of data, baseband signals (information codes ) After the modulation sent to the channel. However, baseband signals are sometimes transmitted directly without modulation. In this case, only suitable for short-range transmission of low-speed baseband signal. Therefore, baseband transmission is actually limited by distance and speed.