Power Line Communications for Enabling Smart Grid Applications Prof. Brian L. Evans, Embedded Signal Processing Laboratory, The University of Texas at Austin Students: Jing Lin, Yousof Mortazavi, Marcel Nassar, Karl Nieman Objective: Develop real-time bi-directional power line communications (PLC) transceiver testbed to aid in system design and algorithm analysis. “LAST MILE” OF SMART GRID CHANNEL IMPAIRMENTS Channel model: Mitigation methods: non-AWGN receiver (cyclostationary noise model accepted into IEEE 1901.2) estimate noise statistics w/ null tones reduced complexity noise shaping equalization, dynamic bit allocation Communications over low and medium voltage infrastructure (at the neighborhood level) smart energy management (dynamic load balancing) automated meter reading device-specific billing home area networks for rural customers filter + + fading Gaussian non-Gaussian Local power area network STANDARDS AND BEYOND Interference sources in PLC systems Estimates of noise power spectra for indoor AC outlet (top) and St. Louis outdoor PLC field trial (bottom) measurements Competing PLC standards G3 and PRIME are international standards for low and medium voltage power lines. Both standards based upon: multicarrier via OFDM mid-frequency (kHz) operation narrowband (lower data rates) Parameter PRIME G3 Transmission band 42-89 kHz 35.9-90.6 kHz Sampling frequency 250 kHz 400 kHz FFT length 512 256 Cyclic prefix length 48 30 Subcarrier spacing 488 Hz 1.65625 kHz OFDM symbol duration 2240 μs 640 μs Max data rate 128.6 kbps 33.4 kbps REAL-TIME PLC TESTBED Objective: Deploy ESPL-developed techniques to mitigate non-Gaussian noise in real-time testbed. Hardware Software National Instruments (NI) controllers stream data NI cards generate/receive analog signals Texas Instruments front end couples to power line Real-time system runs transceiver algorithms Desktop PC running LabVIEW is used as an input and visualization tool to display important system parameters. Our Approach: Multichannel (MIMO) OFDM over Power Line The use of MIMO techniques across multiple phase systems (i.e. phase, neutral and ground) could potentially double or even triple currently-achievable data rates. However, cross-talk induced by coupling between the wires could reduce ultimate throughput. PLC testbed with suite of user-selectable algorithms AFE ECHO TX A TX B RX C RX D RX A RX B TX C TX D NEXT FEXT mode 1 mode 0 Powerline Our prior work on a real-time wired 2x2 MIMO OFDM system achieved 2x data rate using: Far-end crosstalk cancellation Near-end crosstalk cancellation Other adaptive algorithms Bit rates over a 1000 ft CAT-5e cable using 2x2 MIMO OFDM testbed DELIVERABLES Ongoing work: single-transmitter single-receiver (1x1) powerline communication testbed Looking ahead: multiple-transmitter multiple-receiver (MIMO) powerline communication testbed SRC support via Freescale, IBM, and Texas Instruments, GRC Task 1836.063