On The Research Of The Power Line Communications Based On HomePlug1.0 Protocol And The Hardware Realization Of HomePlug1.0 Protocol

The use of ubiquitous electrical wiring as a potential medium for communication signals has been suggested over past generations. Indeed, for some decades now, power line wires have been ?used for low-speed data communication, culminating in such standards and products as LonWorks, CEBus, and X-10, as well as many proprietary systems for the transmission of control and management signals. However, the power line has largely been dismissed as being too noisy and unpredictable to be useful as a practical high-speed communication channel. On the other hand, recent advances in communication and modulation methodologice, as well as in adaptive digital signal processing and error detection and correction, have opened the way for the development of effective medium access control and physical layer protocols that support power line communications(PLC) networks operating at speeds comparable to those obtained from specially wired and more recent wireless local area network In mid-2001,an industrial standards organization called the HomePlug Powerline Alliance, originally founded by 13 companies including Cisco, Motorola, Intel, Panasonic, and Texas Instruments, announced the completion of the HomePlugl.O specification for a l.0Mb/s class in-home power line networking technology based on orthogonal frequency-division multiplexing(OFDM). Products based on this industry standard are enjoying much positive attention in the market press from industry and produce analysts based on performance and case of use. It was clear that HomePlug is now recognized as one of three attractive in-home net working solutions, together with Ethernet and Wi-Fi(IEEE 802.11lx). This thesis presents the studies of the physical layer of power line communications, which is an OFDM-based transmission system. It gives feasible algorithms, and primary implementation of some key modules is discussed as well.Chapter 1 gives a brief survey of the development of Broadband Access networks, after the introduction the main technology of Access networks, we give out the new in-home power line networking technology based on orthogonal frequency-division multiplexing(OFDM), and studies the general content of HomePlugl.O protocol, focusing on the Physical Layer and Mac Layer Specifications of the protocol.Chapter II analyze the channel character of the power line communication channel, constructs a system model taking consideration of power line channels and the channel estimation algorithm based on pilots are investigated.Chapter III, analyze some algorithm to increase the robustness to system nonlinearities in OFDM, compares the advantage and disadvantage of the popular three techniques of PAPR decrease, and proved coded technique is the most effective method for OFDM system.Chapter IV advances a proposed systematic scheme of power line receivers in accordance with HomePlugl.O on the basis of analysis in Chapter III, present the implementation of an OFDM baseband transmission platform based on MPC860T embedded system.