An optimal probabilistic multiple-access scheme for cognitive radios
Type
ArticleAuthors
Hamza, Doha R.Aïssa, Sonia
KAUST Department
Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) DivisionElectrical Engineering Program
Physical Science and Engineering (PSE) Division
Date
2012-09Permanent link to this record
http://hdl.handle.net/10754/562307
Metadata
Show full item recordAbstract
We study a time-slotted multiple-access system with a primary user (PU) and a secondary user (SU) sharing the same channel resource. The SU senses the channel at the beginning of the slot. If found free, it transmits with probability 1. If busy, it transmits with a certain access probability that is a function of its queue length and whether it has a new packet arrival. Both users, i.e., the PU and the SU, transmit with a fixed transmission rate by employing a truncated channel inversion power control scheme. We consider the case of erroneous sensing. The goal of the SU is to optimize its transmission scheduling policy to minimize its queueing delay under constraints on its average transmit power and the maximum tolerable primary outage probability caused by the miss detection of the PU. We consider two schemes regarding the secondary's reaction to transmission errors. Under the so-called delay-sensitive (DS) scheme, the packet received in error is removed from the queue to minimize delay, whereas under the delay-tolerant (DT) scheme, the said packet is kept in the buffer and is retransmitted until correct reception. Using the latter scheme, there is a probability of buffer loss that is also constrained to be lower than a certain specified value. We also consider the case when the PU maintains an infinite buffer to store its packets. In the latter case, we modify the SU access scheme to guarantee the stability of the PU queue. We show that the performance significantly changes if the realistic situation of a primary queue is considered. In all cases, although the delay minimization problem is nonconvex, we show that the access policies can be efficiently obtained using linear programming and grid search over one or two parameters. © 1967-2012 IEEE.Citation
Hamza, D., & Aissa, S. (2012). An Optimal Probabilistic Multiple-Access Scheme for Cognitive Radios. IEEE Transactions on Vehicular Technology, 61(7), 3002–3014. doi:10.1109/tvt.2012.2200051Sponsors
This work was supported by King Abdullah University of Science and Technology (KAUST).ae974a485f413a2113503eed53cd6c53
10.1109/TVT.2012.2200051