Low Voltage Power Line Modem Design And Realization

As a mode of communication, the Powerline Communication makes use of the Power distribution network as corresponding medium. It has already been regarded as one of the main solutions of indoor-network.with the Ethernet or the wireless local area network supplemented, PLC can be available in transmiting high speed data, voice, image and so on multimedia service signal, so it has become a sort of broadband access technology for development favor extremely. It has remarkable superiority that need no new wire, to cover the scope broadly and connection convenience. Since has entered for the 21st centry, along with the breakthrough of the PLC chip technology, its development speeding up obviously, it is facing the practical direction to develop now.The pith of the task is researching and developing the low-voltage powerline communication MODEM, and realizing the consumer wide-band network accessing. The main content and work in this dissertation are as follow:1. We analyse the transmission characteristic of the powerline carrier communication channel. By the experiment, we choose and validate the appropriate model of the powerline channel. It makes the theory foundation for the following design of the powerline MODEM.2. In response to the more complex and changeabel of the low-voltage powerline channel of China, combined with the need of realizing the consumer wide-band access, we adopt the OFDM modulation technology. The application of the OFDM technology in the powerline communication protocol Homeplug1.0 is stressed. The typical application is the chip INT5200, made by INTELLON. It is also the pith device of the powerline MODEM in the design of the dissertation.3. We complete the soft and hard design of the powerline MODEM. On the aspect of the design of circuit, the coupling circuit is difficult: for,on the one hand,it requires the carrier signal having high load-on power,on the other hand,it requires that the 50Hz power signal can't bring oversize interference to the carrier communication system.So we take the"complex coupling technology"that combined the"electromagnetism coupling"and"resistance-capacitance coupling"to resolve the problem. In the design of the circuit of the current source, we adopt the manner of coupling and reduction voltage from the 220V AC powerline interface, it provides power supply for the system, no need for external source. The result of the design proves that these modified scheme is feasible.4. By testing the powerline MODEM communication system, we analyse the three different mode of system and summarize the characteristic the modules. We try to replace the HOST/DTE mode with the PHY mode in the test of system communication, the result prove that the primary function of the two modes are completely identical. The difference is only the communication rate under different circumstances. The test proves that the feasibility and practicability of realizing Broad Band Communication in the Low-Voltage Powerline.