RFID-MIMO Prototype based on GnuRadio

Amelia Jiménez Sánchez

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RFID-MIMO Prototype based on GnuRadio Amelia Jiménez Sánchez 2

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RFID-MIMO Prototype based on GnuRadio Amelia Jiménez Sánchez 3

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Pictures taken from https://www.flickr.com/ Pictures from their websites

RFID-MIMO Prototypebased on GnuRadio

• Theoretical Fundamentals• Goal• SWOT• Implementation• Results • Conclusions

Theoretical Fundamentals

RFID-MIMO Prototype based on GnuRadio Amelia Jiménez Sánchez 5

EPC Gen 2 Standard

Pictures taken from the mentioned Standard

Theoretical Fundamentals

RFID-MIMO Prototype based on GnuRadio Amelia Jiménez Sánchez 9

EPC Query Process

Reader Tag

QUERY

RN16

ACK

PC EPC CRC-16

QREP

1.

2.

3.

4.

5.

PR

PT

FS

PT

FS

PR: Preamble of Reader

PT: Preamble of Tag

FS: Frame-Sync

RN16: 16-Bit Random Number

Diversity combining techniques:

Selection Combining (SC)

Maximal Ratio Combining (MRC)

Equal Gain Combining (EGC)

𝑠𝐶 =

𝑖=1

𝑁𝑟

𝑠𝑅𝑋,𝑖 − 𝑆𝑎,𝑖 ℎ𝑖∗/𝜎𝑖2

Goal

RFID-MIMO Prototype based on GnuRadio Amelia Jiménez Sánchez 10

This thesis discusses the possibility of setting up a prototyping MIMO RFID testbed based on USRP devices and GNU radio implementation for UHF RFID systems.

The performance improvements will be compared to existing commercial and USRP single antenna solutions.

Threats OpportunitiesRFID-MIMO Prototype based on GnuRadio Amelia Jiménez Sánchez 11

• My lack of experience• Limited: time, access to

the laboratory• Start-up

• My interest in the topic• Erasmus scolarship• Guidance of my tutor• Selection of GnuRadio• MIMO prototype

Weaknesses Strengths

• Speed on technologicaladvances

• Competitiveness• Cut in research• Legislation behind technology• Control, surveillance

• GnuRadio: free & open-source• The Comprehensive GNU Radio

Archive Network, Internet• High demand from business and

institutions. • Several fields of application

Implementation

RFID-MIMO Prototype based on GnuRadio Amelia Jiménez Sánchez 12

USRP to_mag MF Reader CR Tag sinkA

to_mag: complex-to-magnitudeMF: Matched FilterA: Amplifier

Reader: Reader-Monitor-cmd-gateCR: Clock RecoveryTag: Tag-Monitor

Gen2 RFID Listener from CGRAN

Two phases:1. Working with a single antenna2. Implement a Diversity Combining Technique (DCT)

Set up the laptop: Ubuntu, UHD, GnuRadio

Implementation (1)

RFID-MIMO Prototype based on GnuRadio Amelia Jiménez Sánchez 13

Command DR M TRext Sel Session Target Q CRC

# of bits 4 1 2 1 2 2 1 4 5

description 1000 0: DR=8

1: DR=64/3

00: M=1

01: M=2

10: M=4

11: M=8

0: No pilot

tone

1: Use pilot

tone

00: All

01: All

10: ~SL

11:SL

00: S0

01: S1

10: S2

11: S3

0: A

1: B

0-15 CRC-5

Setting important parameters: BLF, DR, Miller (M), RTcal, TRcal

𝑅𝑇𝑐𝑎𝑙 = 0𝑙𝑒𝑛𝑔𝑡ℎ + 1𝑙𝑒𝑛𝑔𝑡ℎ = 40 + 80 = 120

1.1 𝑅𝑇𝑐𝑎𝑙 ≤ 𝑇𝑅𝑐𝑎𝑙 ≤ 3 𝑅𝑇𝑐𝑎𝑙

132 ≤ 𝑇𝑅𝑐𝑎𝑙 ≤ 360𝐵𝐿𝐹 =

𝐷𝑅

𝑇𝑅𝑐𝑎𝑙= 320 𝑘𝐻𝑧

Implementation (1)

RFID-MIMO Prototype based on GnuRadio Amelia Jiménez Sánchez 14

tag_log.out empty

RN16? -> d_rn16

1. Picture taken from Google

1

2

2. Picture taken from EPC-RFID INFO

Implementation (2)

RFID-MIMO Prototype based on GnuRadio Amelia Jiménez Sánchez 15

USRP to_mag

MF Reader CR Tag sinkA

USRP to_mag

SC

Rx

Rx2

to_mag MF A Reader CR Tag sink

MRC

to_mag MF A Reader CR Tag sink

Rx

Rx2

Reader -> tag

Preamble found

𝑠𝐶

𝑠𝐶

Selection Combining

Maximal Ratio Combining

USRP

USRP

Results

RFID-MIMO Prototype based on GnuRadio Amelia Jiménez Sánchez 16

Results: Performance achieved for the RFID Listener

RFID-MIMO Prototype based on GnuRadio Amelia Jiménez Sánchez 17

0

20

40

60

80

100

0 10 20 30 40 50 60

%

Distance (cm)

Rx2

0

20

40

60

80

100

0 10 20 30 40 50 60

%

Distance (cm)

SC

L - SR

CRC Error Ratio

CRC Miss Ratio

0

10

20

30

40

50

60

70

80

90

0 10 20 30 40 50 60

%

Distance (cm)

Listener-Success Ratio

Rx

Rx2

SC

0

20

40

60

80

100

0 10 20 30 40 50 60

%

Distance (cm)

Rx

Conclusions

Idea

▪ Slow hunch: incubation

▪ Space: laboratory

▪ Environment

Achievements:

▪ Adapt the project from CGRAN

▪ Design and create a new block using a tool of GnuRadio

▪ Implement a DCT: SCPropose a possibleimplementation for MRC

Keep working on this project

RFID-MIMO Prototype based on GnuRadio Amelia Jiménez Sánchez 18

Pictures taken from https://www.flickr.com/

I appreciate you listening

Thank you

and feel free to ask

RFID-MIMO Prototype based on GnuRadio Amelia Jiménez Sánchez 19