GNU Radio as a Research and Development Tool for RFID Applications

Transcription

1 GNU Radio as a Research and Development Tool for RFID Applications 25 September 2012 Christopher R. Valenta

2 Agenda Overview of RFID and applications RFID/RFID-enabled sensors development GNU Radio as a research and educational tool Conclusions Demonstration Electro(Op+cal-Systems-Laboratory- -EOSL--(-2-

3 Where is RFID? Electro(Op+cal-Systems-Laboratory- -EOSL--(-3-

4 Background on RFID RFID reader transmits continuous wave (CW) signal to environment Tags in range digitally modulate CW signal by changing their size via radar cross section! 15.5 pj/bit! Tags modulated data include identification and sensing information Reader demodulates the backscattered data RFID-Reader- RX- RFID-Tag- Electro(Op+cal-Systems-Laboratory- -EOSL--(-4- RF- Front- End- So<ware- Defined- Radio- TX-

5 RFID Vs. RFID-enabled Sensors & WSN Variety of frequencies (USA FCC ISM Bands) 135 khz, MHz, 433 MHz, 900 MHz, 2.4 GHz, 5.8 GHz Most work concentrated at UHF Digital and analog sensing Recent interest in RFID sensors Intel WISP GE chemical sensor Southern States CMD II GE-Chemical-Sensor- Southern-States-CMD-II- Electro(Op+cal-Systems-Laboratory- -EOSL--(-5-

6 Background on RFID Large number of tags! Cheap! Very simple Increased complexity in reader (transceiver) RX- RFID-Reader- Electro(Op+cal-Systems-Laboratory- -EOSL--(-6- RF- Front- End- So<ware- Defined- Radio- TX-

7 Motivation Lots of developments in RFID technology Novel antennas, sensors, modulation schemes, computation Hardware specific! Software implications Usually entire tag designed with one in mind Integration of technologies is difficult (or impossible) Revisions Expensive Time intensive Electro(Op+cal-Systems-Laboratory- -EOSL--(-7-

8 Why GNU Radio? Availability of DSP blocks Low time to implementation/rapid prototyping Ease of debugging/code readability Modularity Flexibility Protocol, data rate, frequency Reusable code Low latency data processing No other COTS 5.8 GHz RFID systems Lots of freedom Electro(Op+cal-Systems-Laboratory- -EOSL--(-8-

9 Semi-Passive RFID Development Board Development board allows the rapid prototyping of RFID Sensors Microwave structures Antennas Coding/Telecommunications Protocols 4 identical ports allow interchangable daughtercards Daughtercards are controlled via programmable microcontroller on Motherboard Modular hardware and software Electro(Op+cal-Systems-Laboratory- -EOSL--(-9- Semi(Passive- Motherboard- (Microcontroller,-oscillator,-power- circuitry,-usb-debugger,-etc.)- RF-Front- End- (Switches)- Antenna- Analog- Sensor- (ADC)- Digital- Sensor- -(I2C,-SPI)- Demodulator-

10 R.E.S.T. Layout Electro(Op+cal-Systems-Laboratory- -EOSL--(-10- Programming- Port- Reset-BuZon- Microcontroller- TI-(-MSP430F cm- 10-cm- Configurable- BuZon- ADC-Voltage-- Reference- Power-Circuitry- Select-Source- (Programmer- (BaZery- (External- Select-Des+na+on- (MSP430- (Ports- Daughtercard-Port- Status-LEDs-

11 Daughterboards 5.8 GHz RF front end With antenna Without antenna Motion capture board Temperature board Gas sensor array Electro(Op+cal-Systems-Laboratory- -EOSL--(-11-

12 Integrated Motion Capture System Electro(Op+cal-Systems-Laboratory- -EOSL--(-12-

13 Dedicated Motion Capture Tag Gyrometer- Accelerometer- Electro(Op+cal-Systems-Laboratory- -EOSL--(-13- Microcontroller- RF-Switch-

14 Tag Software Flow Diagram Electro(Op+cal-Systems-Laboratory- -EOSL--(-14- Query- Sensors- - Insert-Tag-ID- &-Header- - Calculate- CRC- - Manchester- Encode- - BackscaZer- -

15 Motion Capture System Bi-static arrangement 5.8 GHz Direct Down Conversion Transceiver 120 db dynamic range 12 db noise figure Ettus Research USRP N200 LFRX Daughtercard (DC 30 MHz) Manchester-encoded BPSK Variable data rate Custom telecomm. protocol Header% (3%byte)% Tag%ID% (2%byte)% Accel_Data% (3%byte)% Gyro_Data% (3%byte)% CRC%%%%% (1%byte)% Electro(Op+cal-Systems-Laboratory- -EOSL--(-15-

16 Transceiver Schematic Electro(Op+cal-Systems-Laboratory- -EOSL--(-16-

17 Receiver Software Flow Diagram Electro(Op+cal-Systems-Laboratory- -EOSL--(-17- Channel- Filter- - Correlator- - Automa+c- Gain-Control- - Timing- Recovery- - Constella+on- Receiver- - Framer-sink- - I/Q-Data- Packet- Received-Flag- Unpack-k- bits- -

18 Screenshot Electro(Op+cal-Systems-Laboratory- -EOSL--(-18-

19 Research Tool Backscatter channel is unique Experiments with different modulations Sensor development Passive multiple access Cognitive radio Simulated and real-world data Frequency- S(f) - Electro(Op+cal-Systems-Laboratory- -EOSL--(-19- Flicker-noise- Thermal-noise- DC-Block-

20 Power-Optimized Waveforms (POWs) Benefits:-Increased-range-and-reliability,-mul+ple-access-techniques,-ranging- Challenges:-Genera+on-and-demodula+on- Electro(Op+cal-Systems-Laboratory- -EOSL--(-20-

21 POW Efficiency Improvement Electro(Op+cal-Systems-Laboratory- -EOSL--(-21-

22 Educational Tool Remove complexities of C++ and Verilog Students interact primarily with Python Coding, sensors, headers, modulation Electro(Op+cal-Systems-Laboratory- -EOSL--(-22-

23 Conclusions GNU Radio provides a flexible platform for developing RFID technologies Users Research Labs Industry Hobbyists Undergraduate/Graduate instruction Modular nature allows development of a single piece of hardware/software without significant understanding of system Electro(Op+cal-Systems-Laboratory- -EOSL--(-23-

24 Acknowledgements Funding Shackelford Fellowship from GTRI Thingamagigawerks NSF Career Grant # People Marcin Morys Bashir Akbar Dr. Greg Durgin Electro(Op+cal-Systems-Laboratory- -EOSL--(-24-

25 Questions?

26 Demonstration