A Simpliied Deterministic Approach to accurate Modeling of Transfer Function for the Broadband Power Line Communication

With the deregulation of the telecommunication and electricity markets, great deals of new operators providing some innovative services have appeared. In the telecommunications field, the promise of broad-band internet access with easy installation procedure at low cost may help to gain new customers. The Power Line Communication (PLC) technology is a way to fulfill this function. PLC uses the low voltage (LV) and the medium voltage (MV) networks as communication support (Roka & Urminsky, 2008; Meng & Chen, 2004). It consists in an additional signal carrying data information which is superimposed to the 50/60 Hz power wave. As PLC is easy to install, it can be used to extend the internet coverage to areas that are still badly covered by the other broadband technologies, or to provide high speed internet access to every power socket of building. The modeling of the PLC channel is of fundamental importance, since the quality of the transmission is highly influenced by the characteristics of the channel itself. Principally, channel attenuation depends on the characteristics of the cables (length, per-unit-length parameters, and frequency dependence) and of the loads (Roblot, 2007; Barmada et al., 2006). Several techniques have been proposed to properly simulate the PLC channel. A common practice is to consider the transmission path as a black box and to describe the transmission line by a transfer function (Moreno, 2008 ; Philips, 1999). The system parameters are obtained either from measurements and experimental data or from theoretical derivation (Konaté et al. 2007; Anastasiadou & Antonakoupoulos, 2005). The objective of this chapter is to develop a transfer function model for the LV power line based on the transmission line theory. This model will help the PLC system designer to better understand the channel behavior and to engineer the channel performances under different network configurations and load conditions. This chapter is organized as follows. We start with a representation of the transmission line as two conductors in section 2. We describe the set up experimental in section 3. The next section deals with experimental determination of channel impedance and propagation constant. In section 5, the power channel model is established. In section 6 the proposed deterministic method is generalized to network with N nodes and M branches. Section 7 1