Computer Science – Networking and Internet Architecture
Scientific paper
2008-07-16
Computer Science
Networking and Internet Architecture
Published in IEEE Transactions on Signal Processing, February 2010
Scientific paper
We study the problem of dynamic spectrum sensing and access in cognitive radio systems as a partially observed Markov decision process (POMDP). A group of cognitive users cooperatively tries to exploit vacancies in primary (licensed) channels whose occupancies follow a Markovian evolution. We first consider the scenario where the cognitive users have perfect knowledge of the distribution of the signals they receive from the primary users. For this problem, we obtain a greedy channel selection and access policy that maximizes the instantaneous reward, while satisfying a constraint on the probability of interfering with licensed transmissions. We also derive an analytical universal upper bound on the performance of the optimal policy. Through simulation, we show that our scheme achieves good performance relative to the upper bound and improved performance relative to an existing scheme. We then consider the more practical scenario where the exact distribution of the signal from the primary is unknown. We assume a parametric model for the distribution and develop an algorithm that can learn the true distribution, still guaranteeing the constraint on the interference probability. We show that this algorithm outperforms the naive design that assumes a worst case value for the parameter. We also provide a proof for the convergence of the learning algorithm.
Unnikrishnan Jayakrishnan
Veeravalli Venugopal
No associations
LandOfFree
Algorithms for Dynamic Spectrum Access with Learning for Cognitive Radio does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Algorithms for Dynamic Spectrum Access with Learning for Cognitive Radio, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Algorithms for Dynamic Spectrum Access with Learning for Cognitive Radio will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-41867