Cody Lovejoy Ramsey Doany Ingram School of Engineering Texas State University Kyle Jones PROBLEM STATEMENT • The International Space Station (ISS) • Power Consumption • Current RFID Inventory System • Inefficient •
Download ReportTranscript Cody Lovejoy Ramsey Doany Ingram School of Engineering Texas State University Kyle Jones PROBLEM STATEMENT • The International Space Station (ISS) • Power Consumption • Current RFID Inventory System • Inefficient •
Cody Lovejoy Ramsey Doany Ingram School of Engineering Texas State University Kyle Jones PROBLEM STATEMENT • The International Space Station (ISS) • Power Consumption • Current RFID Inventory System • Inefficient • Wasteful WHAT IS RFID? • Radio Frequency Identification • Credit Cards • Key Cards • Inventory RFID SYSTEM Tag Reader • Passive • RLC Circuit • Induction • Frequency • Antenna • Microchip • Data (128 bit) • Random Number Generator • Handle • Response Delay Time • Antenna • Transceiver • Computer/Software • Modulation /Coding • Demodulation /Decoding CURRENT OPERATION (TDM) Tag Power-Up/Search Query Load 2Q-1 Bit RNG Decrement/Search Query Handle Number ACK Tag Data ACK/Tag Power-Down PROPOSAL • TDM CDMA/DSSS • Conform to Class I Gen. II Specs • 75% reduction in power consumption • Read 5 tags simultaneously • Alien ALR 9900+ RFID Development System THE BASICS • Decrease bit period • Increase transmission speed occupied by bit Increase transmission speed Increase bandwidth CDMA/DSSS • Code Division Multiple Access (CDMA) • Multiplexing • Multiple users occupy channel simultaneously • Orthogonal spreading codes • Direct Sequence Spread Spectrum • Spreading signal bandwidth • Increase transmission speed • Bit redundancy OPERATION 1. Transmitter receives user data 2. Data clocked into XOR circuit 3. Spreading code n times longer than user data sequence clocked into same circuit n times as fast 4. User data signal effectively spread over bandwidth n times as wide as original data 5. Receiver XOR signal with same spreading code to de-spread (decode) signal CDMA-BASED RFID SYSTEM Tag Power-Up/Query Tag Data • Single “beckoning” signal • All tags respond simultaneously (128 bit EPC data) • Reader receives summation of all tag transmissions • Reader demodulates/decodes signal SUPERIORITY OF CDMABASED SYSTEM TDM-Based System CDMA-Based System • “Brute force” method • 1 transmission (any number of tags) • At least 69 transmissions (5 tags, assuming no collisions) • Reader constantly scanning • 98.5% less power consumption DESIGN POSSIBILITIES 1. Physical implementation of CDMA/DSSS • Disable RNG (or set all RNG to select same value) • EPC data encoded according to spreading code 2. Standard Protocol/Time Shift • Use current system to read 5 tags • Record electrical response • Mathematically time shift signals • Demodulate/decode signal 3. Simulation of entire process TEST PLAN • Trace and display single “beckoning” signal • Trace and display summation of tag transmission (at receiver) • Display demodulated and decoded data on PC CONSTRAINTS • Manufacturability • Economies of scale BUDGET • $600 • All RFID hardware and testing equipment provided by Texas State University • No expected additional expenditures WORK BREAKDOWN STRUCTURE TIMELINE 2015 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 3 Tags Begin Design Select Functioning Software Read Tag MUX 1 Tag Design /Write Mods Technique Functioning 5 Tag Tags Mod System Begin (Current Tags Complete Testing System) Implement Characterize Software Current Output AT OUR BOOTH • Alien ALR 9900+ RFID Development System • Images of acquired transmission signals • Mathematical proof of claims