Vector OFDM Transmission Over Non-Gaussian Power Line Communication Channels

Abstract

Most of the recent power line communication (PLC) systems and standards, both narrow-band and broadband, are based on orthogonal frequency-division multiplexing (OFDM). This multiplexing scheme however suffers from the high peak-to-average power ratio (PAPR) which can considerably impact the energy efficiency, size and cost of PLC modems as well as cause electromagnetic compatibility (EMC) issues. This paper investigates the performance of vector OFDM (VOFDM), which has inherently better PAPR properties, over non-Gaussian broadband PLC channels equipped with two nonlinear preprocessors at the receiver. In addition, the low PAPR property of the VOFDM system is exploited to further enhance the efficiency of the nonlinear preprocessors. The achievable gains are studied in terms of the complementary cumulative distribution function of the PAPR, probability of noise detection error and the signal-to-noise ratio at the output of the nonlinear preprocessors. For comparison's sake, the performance of conventional OFDM systems is also presented throughout the paper. Results reveal that the proposed system is able to provide up to 2 dB saving in the transmit power relative to the conventional OFDM under same system conditions, which eventually also translates into a system that is more resilient to EMC limits, reduced cost and size of PLC modems. It is also shown that the achievable gains become more significant as the vector block (VB) size of the VOFDM system is increased.

Impulsive Noise Modeling and Cancellation Strategies Over Power Line Channels

“…Another mitigation technique is proposed in [13] where a nonlinear device is placed at the front end of the receiver. This technique is simple and easy to be implemented; due to these two reasons, this method is widely used in practice [9,14,15]. There are three dierent types of nonlinear preprocessors namely:…”

Optimization of Impulsive Noise Mitigation Scheme for PAPR Reduced OFDM Signals over Powerline Channels

“…In this section, we present an optimization approach to finding the optimal blanking amplitude for mitigating impulsive that have been availed by companding OFDM signals before transmission. Since the IN occurrence cannot be predicted precisely, we maximize the performance of our system through some threshold selection process as in [15], [21] involving some model parameters such as…”

“…Recall that our goal, for example, is to establish the best performing companding transform that can achieve most reduction of the IN in the powerline system, we apply optimization to finding the maximal received SNR and the optimal blanking threshold given the different companding transforms. Consequently, we modify (21) to include F m (x(n)) as…”

EMC Measurements in Indoor Power Line Communication Environments

“…PLCs can play an important role in home networking applications due to the spreading of internet and modern communication technologies. However, the power line network was initially designed to transmit alternating current (AC) to consumers at frequencies 50Hz and 60Hz; hence, several challenges are faced when using this medium for high-data rate transmissions [2,7,9]. Among these is the electromagnetic interference (EMI) issue due to the fact that at high frequencies power lines tend to act as radiating antennas [1].…”