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Introduction to Digital Baseband Signal Waveforms

A digital baseband signal is an electrical waveform that represents digital information, which can be represented by different levels or pulses. There are many types of digital baseband signals (hereinafter referred to as baseband signals). Figure 6-1 shows a few basic baseband signal waveforms, ... Read More

Learning About The Signal

Acknowledgment signals can be divided into energy signals and power signals according to their strengths. Power signals can be divided into periodic signals and aperiodic signals according to whether they are periodic or not. The energy signal is finite in amplitude and duration, its energy is fi... Read More

Frequency Division Multiplexing

When the transmission capacity of a physical channel is higher than the demand of one signal, the channel can be shared by multiple signals. For example, the trunk line of a telephone system usually has thousands of signals transmitted on one optical fiber. Multiplexing is the technology that sol... Read More

Common Code Types for Baseband Transmission

1) The AMI code The full name of the AMI (Alternative Mark Inversion) code is the alternate mark inversion code. blank) remain unchanged. E.g: Message code: 0 1 1 0 0 0 0 0 0 0 1 1 0 0 1 1… AMI code: 0 -1 +1 0 0 0 0 0 0 0 -1 +1 0 0 -1 +1… The waveform corresponding to the AMI code is ... Read More

Nonlinear modulation (Angle Modulation)

When we transmit a signal, whether it is an optical signal, an electrical signal, or a wireless signal, if it is directly transmitted, the signal is easily disturbed by noise, and it is difficult to obtain accurate information at the receiving end. In order to improve the anti-interference abilit... Read More

Binary Digital Modulation

The basic modes of binary digital modulation are: Binary amplitude keying (2ASK)—amplitude change of the carrier signal; Binary frequency shift keying (2FSK)—frequency change of the carrier signal; Binary phase shift keying (2PSK)—phase change of the carrier signal. Differential phase shift keyin... Read More