7/31/2019 Interference in Cognitive Radio Networks Chia Han Lee http://slidepdf.com/reader/full/interference-in-cognitive-radio-networks-chia-han-lee 1/13 Introduction Approximations Examples Conclusions Interference in Cognitive Radio Networks Chia-han Lee University of Notre Dame 2nd Annual North American School of Information Theory, Evanston, IL, August 10-13, 2009 Chia-han Lee Interference to cognitive radio networks
13
Embed
Interference in Cognitive Radio Networks Chia Han Lee
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
7/31/2019 Interference in Cognitive Radio Networks Chia Han Lee
We consider a network which has two groups of users: primaryusers (PU) and cognitive users (CU).
The locations of the primary users and the cognitive usersfollow two independent Poisson point processes (PPP) Φp andΦc with density λp and λc , respectively.
Cognitive users are allowed to transmit only when there is no
primary user within a distance D . Cognitive users who aretransmitting: active cognitive users.
Chia-han Lee Interference to cognitive radio networks
The interference in such network is hard to analyze becausethe process by the primary users (PPP) and the processformed by the active cognitive users (called“hole process ”
here) are not independent.
Approximations for hole process need to be performed!Cluster process seems to be a good candidate.
The overall process is approximated by two independent
processes. In this way, the Laplace transform of theinterference is simply the product of the Laplace transforms of these two independent processes.
Chia-han Lee Interference to cognitive radio networks
Approximation (Matern) interference to PUApproximation (Thomas) interference to PU
Actual interference to CUApproximation (Matern) interference to CU
Approximation (Thomas) interference to CU
(a) (b)
Figure: (a) CCDF of the interference between cognitive users whenD = 0.3. (b) CCDF of the intereference to primary users and cognitiveusers when D = 0.3.
Chia-han Lee Interference to cognitive radio networks
Approximation (Matern) interference to PUApproximation (Thomas) interference to PU
Actual interference to CUApproximation (Matern) interference to CU
Approximation (Thomas) interference to CU
(a) (b)
Figure: (a) CCDF of the interference between cognitive users whenD = 0.6. (b) CCDF of the intereference to primary users and cognitiveusers when D = 0.6.
Chia-han Lee Interference to cognitive radio networks
The cluster process gives good approximations of the hole
process in the cognitive radio network. In particular, theThomas cluster process models better than the Matern clusterprocess.The overall interference can be well approximated by twoindependent processes.
Future work:Derive the bounds for this approximation.
Chia-han Lee Interference to cognitive radio networks