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In a digital communication system, what the receiver receives is the sum of the transmitted signal and the channel noise. The optimal reception of digital signals is based on the minimum error probability as the "best" criterion. Errors considered in this chapter are mai...

Figure 6-6 is a block diagram of a typical digital baseband signal transmission system. It is mainly composed of sending filter (channel signal generator), channel, receiving filter and sampling decision. In order to ensure the reliable and orderly work of the system, th...

When the transmission capacity of a physical channel is higher than the demand for one signal, the channel can be shared by multiple signals, for example, the trunk line of a telephone system often has thousands of signals transmitted in a single fiber. Multiplexing is a technology to solve how t...

(1) AMI code AMI(Alternative Mark Inversion) code is the full name of alternate mark inversion code, its encoding rule is to alternately transform the message code “1″ (mark) to “+1″ and “-1″, while the “0″ (empty sign) remains unchanged. For exampl...

When we transmit a signal, whether it is an optical signal or an electrical signal or a wireless signal, if it is transmitted directly, the signal is susceptible to noise interference, and it is difficult to obtain the correct information at the receiving end. In order t...

The basic ways of binary digital modulation are: binary amplitude keying (2ASK)- the amplitude change of the carrier signal; Binary frequency shift keying (2FSK)- the frequency change of the carrier signal; Binary phase shift keying (2PSK)- Phase change of the carrier si...