17-04-2014, 04:02 PM
Performance Analysis and Modeling of Broadband Power line Communications
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Abstract
Broadband Power line (BPL)
Communications is a promising technique to transmit
communication data, without huge investment. This
paper presents a BPL software simulator which is used to
study the Bit Error Rate (BER) of the Orthogonal
Frequency Division Multiplexing (OFDM) system under
impulsive noise class and multipath effect. The model
also takes into consideration, the error correction coding,
for security. The software simulator is to be used to study
the performance enhancement of the BPL system.
INTRODUCTION
The power line network is not designed for
communications purposes; therefore it suffers from multipath
fading and frequency selectivity. Furthermore, this channel is
distorted by impulsive noise and by severe background noise
[1]. However, the new communication technology operates
in the 1-30 MHz and can deliver data rates up to 200Mbps
[2]. The rationale behind providing high bit-rate data services
exploiting the power grid resides in the vast infrastructure in
place for power distribution, and the penetration of the
service could be much higher than any other wire line
alternative [3]. The medium voltage (MV) broadband over
the power-lines transmission channel has been investigated
with regard to its spectral behavior, the usable bandwidth,
and the end-to-end signal attenuation. It is found that the
aforementioned features depend drastically on the number
and type of branches existing along the end-to-end
broadband over power-lines signal propagation [13]. To
determine the end-to-end transfer function of any MV/BPL
configuration the scattering matrix method is adopted in
another work [14]. Various topologies of MV/BPL
transmission channels have been studied with regard to their
end-to-end signal attenuation and capacity. The analysis and
relevant simulations reveal that broadband transmission via
MV power lines depends drastically on the MV grid topology
and the power constraints imposed to suppress
electromagnetic interference to other services.
CHANNEL MODELING
In addition to the frequency dependent attenuation that
characterizes the power line channel as already explained in
[4], deep narrowband notches occur in the transfer function,
which may be spread over the whole frequency range. These
notches are caused by multiple reflections at impedance
discontinuities. The length of the impulse response and the
number of the occurred peaks can vary considerably
depending on the environment. This behavior can be
described by an ―echo model‖ of the channel as illustrated in
Figure 1.