1. Cody LovejoyRamsey DoanyKyle Jones Ingram School of Engineering Texas State University

2. PROBLEM STATEMENT The International Space Station (ISS) Power Consumption Current RFID Inventory System Inefficient Wasteful

3. WHAT IS RFID? Radio Frequency Identification Credit Cards Key Cards Inventory

4. Passive RLC Circuit Induction Frequency Antenna Microchip Data (128 bit) Random Number Generator Handle Response Delay Time RFID SYSTEM TagReader Antenna Transceiver Computer/Software Modulation /Coding Demodulation /Decoding

5. CURRENT OPERATION (TDM) Tag Power-Up/Search Query Load 2 Q -1 Bit RNG Decrement/Search Query Handle Number ACK Tag Data ACK/Tag Power-Down

6. 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

7. THE BASICS Decrease bit periodIncrease transmission speed Increase transmission speedIncrease bandwidth occupied by bit

8. 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

9. 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

10. 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

11. 1 transmission (any number of tags) 98.5% less power consumption “Brute force” method At least 69 transmissions (5 tags, assuming no collisions) Reader constantly scanning SUPERIORITY OF CDMA- BASED SYSTEM TDM-Based SystemCDMA-Based System

12. 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

13. TEST PLAN Trace and display single “beckoning” signal Trace and display summation of tag transmission (at receiver) Display demodulated and decoded data on PC

14. CONSTRAINTS Manufacturability Economies of scale BUDGET $600 All RFID hardware and testing equipment provided by Texas State University No expected additional expenditures

15. WORK BREAKDOWN STRUCTURE

16. TIMELINE JanFebMarAprMayJunJulAugSepOctNovDec 2015 Read /Write Tags (Current System) Select MUX Technique Characterize Current Output Design Tag Mods Mod Tags Begin Software Design Implement Software 1 Tag Functioning 3 Tags Functioning 5 Tag System Complete Begin Testing

17. AT OUR BOOTH Alien ALR 9900+ RFID Development System Images of acquired transmission signals Mathematical proof of claims