Knowledge

Direct Sequence Spread Spectrum (DSSS) Communication – Communication Principle

Principle: The principle of the Direct Sequence Spread Spectrum system is very simple. For example, a string of information to be sent is expanded to a very wide frequency band through PN code. At the receiving end, the information sent is retrieved by correlating the spread spectrum signal with ... Read More

Introduction to Error Vector Magnitude (EVM)

EVM: abbreviation of Error Vector Magnitude, which means error vector amplitude. The digital signal frequency band transmission is to modulate the baseband signal at the sending end, send it to the line for transmission, and then demodulate it at the receiving end to recover the original baseband... Read More

Data Transmission Mode and Working Principle

Working principle: After any node of the switch receives the data transmission command, it quickly searches the address table stored in the memory to confirm the connection location of the network card with the MAC address and then transmits the data to the node. If the corresponding location is ... Read More

How To Judge Quality of Optical Modules

Various third-party optical modules on the market have great advantages in cost compared with the original optical modules, which can effectively solve the problem of the high deployment cost of optical modules. However, some people still worry about the quality of compatible optical modules. HDV... Read More

Ethernet port – RJ45

   As shown in the above figure, we can understand the appearance of RJ45 according to the picture, but not all RJ45 interfaces like the one in the above figure are RJ11 interfaces, which will not be discussed temporarily. The switches are arranged side by side with multiple RJ45 ports, which ca... Read More

Compatibility of Optical Modules

Generally speaking, the compatibility of optical modules refers to whether the modules can work normally on communication equipment of different brands and manufacturers. The technology content of optical modules is relatively low, and their introduction is relatively simple. As a result, many t... Read More