Hybrid Powerline/Wireless Diversity for Smart Grid Communications
Smart Grids refer to evolved power grids that can intelligently monitor and control energy flows in order to improve the efficiency and reliability of power delivery. Adding such intelligence throughout the grid requires deployment of a two-way communication network between smart meters at the consumer residential sites, and command and control centers operated by local/regional utility. This communication network enables the utility to collect data about network events which can be leveraged to optimally manage the power grid. Smart Grids are supported by heterogeneous networks that employ both wireless and powerline communication (PLC) technologies, since no single solution fits all scenarios. The channel and noise statistics experienced by powerline and wireless transmissions are independent and of a nonidentical nature. In this dissertation, I propose to exploit the diversity provided by the simultaneous trans- mission of the same information over both powerline and wireless links as a way to enhance the overall system reliability. In particular, I propose efficient techniques to combine the received signals of the NB-PLC and wireless links for both coherent and differential modulation schemes while considering the impulsive nature of the noise on both links. In addition, I derived closed-form expressions for the average bit-error-rate of the proposed combining techniques. Furthermore, I present simulation results to quantify the performance gains achieved by the proposed receive diversity combining techniques compared to conventional combining techniques. In addition, I describe a real-time NB-PLC/wireless testbed proto- type for the proposed combining techniques to demonstrate the enhanced performance over a single link. I considered practical implementation issues such as packet synchronization for both PLC and wireless and correction of the frequency offset due to oscillator mismatch.