Halim Yanikomeroglu Mohammad G. Khoshkholgh, Keivan Navaie - - PowerPoint PPT Presentation

ICC 2010, Cape Town South Africa

Halim Yanikomeroglu Department of SCE Carleton University, Ottawa, Canada Email: halim@sce.carleton.ca

Mohammad G. Khoshkholgh, Keivan Navaie Department of ECE Tarbiat Modares University, Tehran, Iran Email: keivan.navaie@ieee.org

11/23/2010

11/23/2010

Existing spectrum policy has full allocation

but poor utilization

Spectrum sharing proposed to improve

spectral efficiency

Primary service is the licensee Secondary service utilizes Opportunistic

Spectrum Access (OSA)

Secondary service detects and makes use of

the spectrum holes/white spaces

Interference threshold is defined as a metric

to detect spectrum holes/white spaces

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To protect the primary service from

unacceptable QoS degradation

access to the white spaces subject to no/minimum QoS degradation at the primary receiver

manage the imposed interference at the primary receiver to satisfy the interference threshold

To improve the spectral efficiency

accommodate as much secondary service users as possible

utilize sophisticated power control mechanism utilize accurate spectrum sensing procedure . . .

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To analyze the impacts of

To analyze the impacts of the secondary service the secondary service parameters & parameters & the wireless environment on the wireless environment on the the primary service outage probability primary service outage probability

• a closed form

a closed form is derived is derived for the primary for the primary service outage service outage probability derived based probability derived based on

• n the

the transmit power of transmit power of the the secondary secondary service and miss detection probability of service and miss detection probability of the the spectrum sensing spectrum sensing

• the

the maximum secondary service transmitter node maximum secondary service transmitter node density is density is obtained for a

• btained for a given outage

given outage probabili probability ty constrain constraint of t of the the primary service primary service

• an upper bound is

an upper bound is obtained to

• btained to the

the achievable capacity achievable capacity

• f the primary
• f the primary service

service

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Primary Service Transmitter Primary Service Receiver Secondary Service Transmitters Secondary Service Receivers

The secondary service transmitters

distributed based on a Homogenous Point Process where A is area of region R.

All secondary service transmitters have

identical ROC curves, i.e., equal false alarm, , and miss detection probability

{ } ( )

Pr !

s

k A sA

k SS in region R e k

λ

λ

−

=

ε

δ

If the spectrum is idle and the spectrum sensing wrongly recognize the spectrum status as busy, a false alarm is occurred. miss detection is occurred in cases where the spectrum is busy and it is mistakenly recognized as idle

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The channel is available with probability The set of secondary users which experience

miss detection with density

Channel power gain between primary

transceiver is exponentially distributed

Channel power gain among secondary

transmitters and the primary receiver are independent exponential random variables

1

i b

p p = −

{ }

| 1(missdetectionindicator)

i i

X D ∏ = ∈∏ = %

s b

p λ δ

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Received interference at the primary receiver

in miss detection experiences is the secondary service transmission power is the distance-dependent path-loss attenuation is a power law shot noise process

, s i sp i i

I S X g

α ϕ − ∈∏

=∑

s

S

i

X

α −

Iϕ

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Obtaining the primary service outage

probability surrounding by a secondary network distributed based on Homogenous Point Process

Obtain the maximum number of the

secondary transmitters per unit area to satisfy the primary service outage probability constraint

Stochastic Geometry results are utilized for

analysis

ξ

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Primary service SINR We show that the Primary service outage

probability is

p p p

S R g SINR W I

α ϕ −

= +

{ }

( )

/ 2 2

Pr 1

s th p

p

• ut

p th S R L S th W p

P SINR R e S

α

γ α λ α

γ γ μ

⎛ ⎞ − ⎜ ⎟ ⎜ ⎟ ⎝ ⎠

= < ⎛ ⎞ = − Φ ⎜ ⎟ ⎜ ⎟ ⎝ ⎠

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We show that the maximum secondary

transmitter density for satisfying the primary service outage probability

2/ * 2

1 ln1

s th s p b

S S R L p

α

γ ξ λ δ

−

⎛ ⎞ − = ⎜ ⎟ ⎜ ⎟ ⎝ ⎠

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The primary service capacity by ignoring the

effect of AWGN

( ) ( )

( )

/2 2

1 log 1 2 1 log 1 / 2 1 2

p p p s

C E SINR S LR S

α

λ α

−

= + ⎛ ⎞ ≤ + Γ + ⎜ ⎟ ⎝ ⎠

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A closed-form expression was derived for the

primary service outage probability in Rayleigh fading environment

The maximum secondary service transmitter

density was obtained to satisfying the primary service outage constraint

The primary service capacity was analyzed

and an upper bound was derived

17

Thanks!

Mohammad G. Khoshkholgh, khoshkholgh@modares.ac.ir Keivan Navaie keivan.navaie@ieee.org Halim Yanikomeroglu halim@sce.carleton.ca