Power-line communication (PLC) technology uses the existing power cable infrastructure for communication purposes [1]. This technology does not involve any installation costs due to the readily availability of power-line grids. The electric power lines are classified into the high (larger than 100 kV), medium (1-100 kV) and low (smaller than 1 kV) voltage networks. High-voltage lines are usually not used for data transmission due to the excessive noise. Medium-voltage lines are routed from the substations to the neighborhood transformers, and can be used to form the backbone of data over power-line infrastructure. Low-voltage lines are routed from the neighborhood transformers to homes.
Orthogonal frequency division multiplexing (OFDM) modulation has been proposed as the modulation scheme for PLC networks due to its many desirable features [1]. However, if the length of the channel impulse response L is longer than that of the cyclic prefix (CP), inter-symbol interference (ISI) will arise. One of the possible solutions to combat ISI in PLC networks is to use a channel shortener, which is commonly known as time-domain equalizer (TEQ), at the receiving end to shorten the channel. A number of the TEQ methods [2-4] have been proposed for digital subscriber loop (DSL) systems. However, no thorough study on the implementation of TEQs over medium-voltage power-line communication (MV-PLC) networks has been reported yet. This under-reported area urges a motivation to investigate the potential performance improvements with a TEQ incorporated in MV-PLC networks. Different from the DSL channels, the increase of the number of branches along the transmission path increases the L [5], thus giving rise to strong ISI in the MV-PLC channels. In addition, the MV-PLC channels are worsen and afflicted with colored background noise, narrowband interference and impulsive noise, and thus exhibit remarkable differences from the DSL channels. Therefore, the aim of our study is to make the performance assessments on three major TEQ methods in such a hostile medium, and to provide the insights on the deployment of TEQs in MV-PLC networks.
1. S. Galli and O. Logvinov, “Recent developments in the standardization of power line communications within the IEEE,” IEEE Communications Magazine, vol. 46, no. 7, pp. 64-71, July, 2008.
2. N. Al-Dhahir and J. M. Cioffi, “Efficiently computed reduced-parameter input-aided MMSE equalizers for ML detection: A unified approach,” IEEE Trans. Inform. Theory, vol. 42, pp. 903-915, May, 1996.
3. P. J. W. Melsa, R. C. Younce, and C. E. Rohrs, “Impulse response shortening for discrete multitone transceivers,” IEEE Trans. Commun., vol. 44, pp.1662-1672, December, 1996.
4. G. Arslan, B. L. Evans, and S. Kiaei, “Equalization for discrete multitone receivers to maximize bit rate,” IEEE Trans. Signal Processing, vol. 49, pp. 3123-3135, December, 2001.5. J. Anatory, 5. N. Theethayi, M. M. Kissaka, N. H. Mvungi, and R. Thottappillil, “The effects of load impedance, line length, and branches in the BPLC-transmission-lines analysis for medium-voltage channel,” IEEE Transactions on Power Delivery, vol. 22, no. 4, pp. 2156-2162, October, 2007.
(From my paper.)
