IN-VEHICLE POWERLINE COMMUNICATION USING SOFTWARE-DEFINED RADIO by ROEE BAR B.Sc., Technion - Israel Institute of Technology, 2007 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF APPLIED SCIENCE in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Electrical and Computer Engineering) The University of British Columbia (Vancouver) August 2016 c Roee Bar, 2016 Abstract Powerline communication is an attractive solution for in-vehicle communi- cation. However, the research of communication over powerlines requires field-testing and full access to communication protocol layers, particularly to the physical and the Media Access Control (MAC) layers. This ability can be accomplished through the use of software-defined radio along with real- time signal processing executed on a personal computer. In this work, we present the design and implementation of an IEEE 1901-based transceiver aimed for vehicular powerlines, written for GNU Radio and operated on Ettus Universal Software Radio Peripheral (USRP) N210 hardware. The software components include a C++ physical layer signal processing li- brary and several complementary GNU Radio blocks including a MAC layer block written in Python. The implemented capabilities include sev- eral channel estimation methods, a noise power spectral density estimator and an adaptive bit loading algorithm. We make all the software compo- nents available as an open source project to facilitate further development by the broader research community. We then show experimental results obtained with the system applied to a vehicle harness and a real vehicle powerline network. In the first part of the experiments, we demonstrate the correctness of the implementation, compare between several channel estimation methods, and test the system performance. In the second part, we examine the feasibility of reliable communication with IEEE 1901 over powerlines in a car. Our experiments show that IEEE 1901 along with the implemented receiver algorithm are capable of operating in the scenarios tested. The vehicular impulsive noise is identified as the primary cause for errors. In particular, our experiments show that it affects mainly the frame synchronization. Hence we believe that further investigations of in-vehicle ii powerline communication should focus on alleviating the effect of impulse noise on synchronization. iii Preface The work presented in this thesis was completed in the Department of Elec- trical and Computer Engineering at the University of British Columbia un- der the supervision of Dr. Lutz Lampe. This thesis is original, unpublished, independent work by the author, R. Bar. This includes, but is not limited to, literature review, simulation design and implementation, coding, data analysis, and manuscript writing. Dr. Lampe contributed to the work as a secondary author by providing guidance and supervision throughout. iv Table of Contents Abstract ................................... ii Preface.................................... iv Table of Contents.............................. v List of Tables ................................ ix List of Figures................................ x List of Symbols............................... xii Glossary................................... xiv Acknowledgements ............................ xvi Dedication..................................xvii 1 Introduction............................... 1 1.1 In-Vehicle Communication Networks ............. 2 1.1.1 Communication Protocols................ 2 1.1.2 Next Generation Network................ 3 1.2 Powerline Communication.................... 4 1.2.1 Powerline Communication Standards......... 5 IEEE 1901 ......................... 7 1.3 Software-Defined Radio-Based Implementation ....... 7 1.4 Related Works........................... 9 1.5 Contribution............................ 10 1.6 Organization............................ 10 v 2 Powerline Communication System Description.......... 12 2.1 PHY Transmitter ......................... 12 2.1.1 Overview ......................... 12 2.1.2 Preamble Generation................... 14 2.1.3 Encoder .......................... 15 Frame Control Encoder ................. 15 Payload Encoder..................... 16 Turbo Convolutional Encoder.............. 17 2.1.4 Symbol Generation.................... 18 2.2 PHY Receiver ........................... 20 2.2.1 Overview ......................... 20 2.2.2 Frame Detection ..................... 21 2.2.3 Symbol Alignment.................... 22 2.2.4 Phase Estimation..................... 23 2.2.5 Symbol Demodulation.................. 25 2.2.6 Decoder .......................... 27 Frame Control Decoder ................. 27 Payload Decoder..................... 28 2.3 Channel Estimation........................ 29 2.3.1 Sounding Method .................... 29 2.3.2 Payload Method ..................... 31 2.3.3 Preamble Method..................... 34 2.4 Noise Power Spectral Density Estimation........... 34 2.5 Adaptive Bit Loading....................... 35 2.5.1 Incremental Algorithm.................. 37 2.6 MAC Layer ............................ 38 2.6.1 MAC Frame........................ 38 2.6.2 MAC Protocol Data Unit (MPDU)........... 39 2.6.3 Channel Access...................... 39 Sounding Process..................... 40 2.7 Impulse Noise Model....................... 40 2.7.1 Damped Sine Wave.................... 42 Fourier Analysis ..................... 43 vi 2.7.2 Periodic Impulse Noise ................. 45 3 Implementation Details........................ 46 3.1 Overview.............................. 46 3.1.1 Development Platform.................. 46 3.1.2 Structure.......................... 47 3.2 Ettus USRP N210......................... 48 3.3 Lightplc .............................. 49 3.4 GNU Radio Blocks ........................ 51 3.4.1 PHY Hierarchical Block................. 51 3.4.2 PHY Rx Block....................... 52 State Machine....................... 53 Incoming Messages.................... 54 3.4.3 PHY Tx Block....................... 55 State Machine....................... 55 Incoming Messages.................... 56 3.4.4 MAC Block ........................ 56 State Machine....................... 57 Incoming Messages.................... 57 User Parameters ..................... 60 3.4.5 APP Layer Blocks..................... 61 3.4.6 Impulse Source Block .................. 61 3.4.7 Transceiver ........................ 61 3.5 Known Limitations........................ 63 4 Experimental Results.......................... 65 4.1 System Setup ........................... 65 4.1.1 PHY Parameters ..................... 66 4.1.2 MAC Layer Parameters ................. 67 4.1.3 Power Spectral Density ................. 69 4.2 Car Cable Harness (White Noise)................ 70 4.2.1 Channel Estimation ................... 72 Comparison of Channel Estimation Methods . 73 vii 4.2.2 Bit Loading ........................ 74 Bit Error Rate....................... 76 4.2.3 Summary ......................... 78 4.3 Car Cable Harness (Impulse Noise)............... 79 4.3.1 Noise Generation..................... 79 4.3.2 Noise PSD......................... 81 4.3.3 Bit Loading ........................ 81 4.3.4 Performance........................ 82 Bit Error Rate....................... 83 PHY Rate ......................... 84 Sync Error......................... 85 Block Error ........................ 86 4.3.5 Summary ......................... 86 4.4 Real Car .............................. 88 4.4.1 Results........................... 89 Car-Off........................... 89 Turn-Signal-On...................... 90 Lights-Toggle....................... 90 Wipers-On......................... 91 Engine-On......................... 93 4.4.2 Summary ......................... 94 5 Conclusions............................... 97 5.1 Conclusions ............................ 97 5.2 Future Work............................ 98 Bibliography ................................ 100 A Derivations ............................... 107 A.1 Rice Parameter Estimation.................... 107 A.2 OFDM Symbol Energy...................... 108 A.2.1 Generated Symbol .................... 108 A.2.2 Received Symbol..................... 109 viii List of Tables 2.1 Modulation Types in IEEE 1901................. 19 4.1 Modified IEEE 1901 Properties ................. 68 4.2 Implementation-Specific Parameters.............. 68 4.3 Impulse Noise Parameters.................... 80 4.4 Car Car-Off Results........................ 90 4.5 Car Lights-Toggle Results .................... 93 4.6 Car Wipers-On Results...................... 93 4.7 Car Engine-On Results...................... 95 ix List of Figures 2.1 PPDU Structure.......................... 13 2.2 Preamble Structure........................ 15 2.3 PPDU Generation......................... 16 2.4 IEEE 1901 Constituent Encoder................. 18 2.5 Modified Constituent Encoder ................. 18 2.6 PPDU Receive Path........................ 21 2.7 Preamble Correlation....................... 23 2.8 Master-Slave Channel Access.................. 41 2.9 Damped Sine Wave........................ 43 2.10 Damped Sine Wave Fourier Transform............. 44 3.1 Implementation Block Diagram................. 47 3.2 USRP N210 Architecture..................... 49 3.3 PHY Hierarchical Block ..................... 52 3.4 PHY Rx State Machine...................... 53 3.5 PHY Tx State Machine...................... 55 3.6 MAC Master State Machine................... 58 3.7 MAC Slave State Machine.................... 59 3.8 Two-Transceiver Flow