Development of a generic communication platform for wireless sensor networks

IT 15017

Examensarbete 30 hp December 2015

Development of a generic

communication platform for wireless sensor networks

Anton Danielsson Jakob Ågren

Institutionen för informationsteknologi Department of Information Technology

Teknisk- naturvetenskaplig fakultet UTH-enheten

Besöksadress:

Ångströmlaboratoriet Lägerhyddsvägen 1 Hus 4, Plan 0 Postadress:

Box 536 751 21 Uppsala Telefon:

018 – 471 30 03 Telefax:

018 – 471 30 00 Hemsida:

http://www.teknat.uu.se/student

Abstract

Development of a generic communication platform for wireless sensor networks

Anton Danielsson and Jakob Ågren

The purpose of this theses work has been to develop a physical layer wireless network emulator using commercially available hardware. As there are no custom built hardware components a number of compromises have to be made, and solutions to minimize impact on emulator performance have been found. The emulator is designed to handle real-time, two-way communication with up to 8 sensor nodes and is tested to be working using IEEE 802.15.4 compliant wireless sensor nodes. Emulator performance is evaluated, and some avenues to circumventing the emulator shortcomings are presented. Channel reconstruction, using pre-recorded data together with the emulator is also explored. Sensor node transceiver performance is investigated, as well as the possible impact on emulation correctness when connected nodes are non ideal. In the appendix some commonly used techniques for programming field programmable gate arrays are illustrated by an example.

Tryckt av: Reprocentralen ITC ISSN: 1401-5749, UPTEC IT15 017 Examinator: Lars-Åke Nordén Ämnesgranskare: Tomas Olofsson Handledare: Anders Ahlén

cij

Xⁱⁿ X^out

C

zi

•

•

•

•

•

s(t) fc fc

fc

x(t) = s(t)sin(2πfct + ϕ) = s(t)sin(ωct + ϕ),

f Spectral density

−ωc ωc

Baseband

P assband P assband

ωc = 2πfc

s(t) x(t)

ωc

s(t) = I(t) + iQ(t).

x(t)

x(t) = a(t)cos(ωct + θ(t))

−sin(ω^ct) Im(s)

cos(ωct) Re(s) xQ(t)

xI(t) Q(t)

I(t)

x(t) s(t)

a(t) θ(t)

ωct

cos(a + b) = cos(a)cos(b)− sin(a)sin(b) x(t)

x(t) = xI(t)cos(ωct)− x^Q(t)sin(ωct)

xI(t) = a(t)cos(θ(t)) xQ(t) = a(t)sin(θ(t))

e^itω0f (t)↔ �f (ω− ω⁰)

f (ω)� f (t)

ω Spectral density

Baseband P assband

ωc

−ω

ω

π ωt

2 π 3π

2 2π

cos(t) sin(t) ω

•

•

•

•

•

Σ

•

•

A B

C

CH 26

H C 26

CH26 CH26

CH C 26

26 H

A B

C

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22

CH

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CH 23

CH25�→CH21 CH

25�→CH 23

CH 26�→

CH 21 CH

26

CH �→

22

C

X^CH24,X^CH25 X^CH26

xCH21= c11xCH24+ c21xCH25+ c31xCH26

xCH22= c12xCH24+ c22xCH25+ c32xCH26

xCH23= c13xCH24+ c23xCH25+ c33xCH26,

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

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 xCH21

xCH22

xCH23

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





c11 c21 c31

c12 c22 c32

c13 c23 c33



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 xCH24

xCH25

xCH26





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

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 xCH21

xCH22

xCH23





 , C =







c11 c21 c31

c12 c22 c32

c13 c23 c33





 , X^out=





 xCH24

xCH25

xCH26





 .

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C

C C

z1= c12= c21, z2= c13= c31, z3= c23= c32

C =



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0 z1 z2

z1 0 z3

z2 z3 0



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 .

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z1

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3 z

z1 z2

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C¹¹

C¹²

C¹³

C²¹

C²²

C²³

C³¹

C³²

C³³

×

×

×

×

×

×

×

×

×

X^CH21 X^CH22 X^CH23

+ + +

DU T

Inputchannels

Output channels

cij

Xⁱⁿ X^out

C

f Spectral density

CH24 T XA

CH25 T XB

CH26 T XC

A A

B B

C

C

CH23 RXC

CH22 RXB

CH21 RXA

5M hz

z₂² z₃² z₁²

zi

8 8 Σ

|x| ⁶⁴

ω[n] =±[2.5, 7.5, 12.5, 17.5]Mhz −ω[n]

•

•

•

•

•

•

•

•

0 2 4 6 8 10 12 14 16 18 20

−80

−60

−40

−20 0

0 2 4 6 8 10 12 14 16 18 20

−20

−15

−10

−5 0

40M Hz

[−1, 1]

[−1, 1]

2.445+2.48

2 = 2.4625

[0, 1]

m = [−75, 0], d = m

20, C = 10^d

C

C

−70 −60 −50 −40 −30 −20 −10 0

−80

−60

−40

−20 0

[−23, −30]�

[−54, −60]

−60 −40 −20 0

−100

−80

−60

−40

−20

−60 −40 −20 0

−0.1 0 0.1

−55 −50 −45 −40 −35 −30 −25 −20 −15 −10

−60

−50

−40

−30

−20

RSSI =−30

Gain=−25

RSSI =−23

Gain=−12

RSSI =−54

Gain=−41

RSSI =−60

Gain=−52

−70 −60 −50 −40 −30 −20 −10 0

−4

−2 0 2 4 6

−49dB

−54dB

5.4dB

−2.5dB

−16.6dB

−26.7dB ∆error=7.9dB

∆gain = 10.1dB

dynamic range (dB) = 20∗ log10(2^#bits).

≈

•

•

−70 −60 −50 −40 −30 −20 −10

−4

−2 0 2

4 ^3.8dB

−3.4dB

−16.9dB

−25.8dB ∆error=7.2dB

∆gain = 8.9dB

•

≈

−100 −90 −80 −70 −60 −50 −40 −30 −20 −10 0

−100

−80

−60

−40

−20 0

y =−85 dB

x =−82.5 dB

µ

µ µ

µ

µ

µ

µ

µ

µ µ µ µ

0 100 200 300 400 500 600 700 800 900 1,000

−70

−60

−50

−40

C5

C4

C1

C2

C3

C1

C2

C3

C4

C5

C4 C5

0 10 20 30 40 50 60

−80

−70

−60

−50

−40

C1 C2 C3

0 10 20 30 40 50 60

−80

−70

−60

−50

−40

2.462 2.464 2.466 2.468 2.470 2.472 2.474 2.476 2.478

−80

−60

−40

−20 0

−33dB

[GHz]

CH23 CH24 CH25

A B

C

...

T S O R N G

leakage

weak ...

...

≤ −15 62

−10 53

−5 30

+5 45

+10 54

≥ +15 62

µ

µ µ

x + y

14ns⁻¹

•

•

•

•

•

•

4ns⁻¹

•

•

•

•

•

•

y1, y2, y3, y4

acc

yn

•

•

•

•

•

•