Design Of High-Speed Power-line Communication Based On OFDM Technology

With the development of communication technology, the demand for high speeddigital communication increases rapidly. How to achieve the connection of internetand how to achieve home network become the focuses of the present research. Moreand more people begin to research how to achieve high-speed digital communicationthrough power-line and now home plug 1.0, a protocol about PLC, has beenestablished. However there is no mature production about PLC in China. Because ofthis background, this paper analyzes the characters of power-line channel, and thendesigns a high speed communication system based on OFDM technology.OFDM, a multi-carrier technology, is to transfer high-speed serial data streamsto low-speed parallel data sub-streams and increase the duration of symbols, whichcan reduce the ISI caused by multi-path channel. Now, OFDM is widely used inhigh-speed digital communication, such as DVB, DAB, WLAN and so on. However,there still have some problems of OFDM system. For example, the system is sensitiveto frequency off-set and the system has a high PAPR.This paper designs the structure of the whole system and gives the parameters ofthe design. At the same time, this paper focuses on the key algorisms of base-banddigital signal processing: synchronization, channel estimation and equalization,control of PAPR and channel coder and decoder. 2D-Pilots are employed to estimatethe channel. The system uses DFT-based algorism to estimate the channel infrequency domain and linear interpolation in time domain. The short training symbolsare employed to get the time synchronization and coarse estimation of frequencyoff-set;then the long training symbols are employed to acquire the fine estimation offrequency off-set;finally system uses pilots to trace the frequency offset. RS code andconvolutional code are employed as channel code. Finally the paper simulates thesystem in CCSS of synopsys, and gets a favorable result of the system performance.