Powerline Communications for Enabling Smart Grid Applications

1. GRC Task 1836.063, Prof. Brian L. Evans, Embedded Signal Processing Laboratory, The University of Texas at Austin Students: Jing Lin, YousofMortazavi Objective: Quantify communication performance vs. complexity tradeoffs in a real-time bi-directional MIMO PLC testbed. LAST MILE OF SMART GRID Real-time PLC Prototype • 1x1 Real-time Bidirectional Powerline Communications Testbed • Local Area Power Network • We focus on the “last mile” of the smart grid from a concentrator to its subscribers along low-voltage lines. • The applications include: • automatic meter reading • device-specific billing • smart energy management, • home area network, etc. Powerline Communications for Enabling Smart Grid Applications STANDARDS AND BEYOND • Medium-Frequency Narrowband PLC Standards G3and PRIMEare prevalent standards for medium-frequency (kHz) narrowband (~100kHz) multicarrier powerline communications on low-voltage lines. Data is transmitted over multiple subcarriers, a.k.a. orthogonal frequency division multiplexing (OFDM). PowerlineChannel Impairments • By transmitting independently over many subcarriers, OFDM is capable of coping with the frequency-selective channel. The demodulation of OFDM symbols by discrete Fourier transform spreads out and thus mitigate the effect of the impulsive noise. • To enable more robust and efficient communication, adaptive signal processing methods need to be developed: • Peak-to-average ratio reduction • Channel shortening equalization to compensate for extra long delay spread • Bit allocation • Impulsive noise statistical estimation and mitigation by non-linear filtering or iterative decoding, etc. • Multichannel (MIMO) OFDM over Powerline The availability of three phases on low-voltage lines and three copper wires (i.e. phase, neutral and ground) in the inhome single-phase power systems allows potentially double or even triple the data rates. However, the presence of cross-talk induced by energy coupling across the phases or wires may cause significant degradation in achievable data rate. Powerline RX A TX A AFE AFE mode 0 ECHO TX C RX C NEXT FEXT NEXT RX B TX B AFE AFE mode 1 TX D RX D Our prior work on a real-time 2x2 MIMO OFDM wired testbed achieved 2x data rate vs. the 1x1 system by far-end, near-end crosstalk cancellation methods, and other adaptive algorithms. Deliverables • Ongoing work: single-transmitter single-receiver (1x1) powerline communication testbed • Looking ahead: multiple-transmitter multiple-receiver (MIMO) powerline communication testbed