Title :
Goodput maximization in opportunistic spectrum access radio links with imperfect spectrum sensing and fec-based packet protection
Author :
Bonuccelli, M.A. ; Ermini, D. ; Pescosolido, Loreto ; Petrioli, Chiara
Author_Institution :
Dipt. di Inf., Univ. of Pisa, Pisa, Italy
Abstract :
We consider a cognitive radio scenario where the communication between two secondary users (SUs) exploits opportunistic spectrum access (OSA) over a wireless channel licensed to primary users (PUs). Assuming a slotted MAC over a single frequency channel and imperfect spectrum sensing, we address the problem of determining the packet size and Forward Error Correction (FEC) coding rate that maximize the SU communication goodput, i.e., the amount of payload bits correctly received in the unit time. Assuming a Markovian model for the PU activity, a saturation regime for the SU, and periodic channel sensing, we find out the mean time between two consecutive packet transmissions and derive approximate analytical expressions, in closed form, which provide upper and lower bounds on the SUs goodput. Such expressions show the dependence of the SU goodput on packet size, FEC coding rate, signal to noise plus interference ratio, amount of resources allocated to sensing, packet overhead, and primary traffic statistics. We provide simulation results showing that the derived analytical expressions are very close to the actual system performance. We also evaluate the sensitivity of the optimal packet size and FEC coding rate pair to the operational conditions represented by the received power and the PU traffic load, showing that the optimal pair is very sensitive to the former, and only moderately affected by the latter.
Keywords :
Markov processes; channel coding; cognitive radio; forward error correction; radio links; radio spectrum management; telecommunication traffic; wireless channels; FEC coding rate; FEC-based packet protection; Markovian model; OSA; PU activity; PU traffic load; SU communication goodput; approximate analytical expressions; cognitive radio; consecutive packet transmissions; forward error correction coding; goodput maximization; imperfect spectrum sensing; lower bounds; opportunistic spectrum access radio links; packet overhead; packet size; payload bits; periodic channel sensing; primary traffic statistics; primary users; secondary users; signal to noise plus interference ratio; single frequency channel; slotted MAC; upper bounds; wireless channel; Cognitive radio; FEC; Markov processes; Opportunistic Spectrum Access (OSA); packet size; recurrent events; spectrum sensing; throughput maximization;
Conference_Titel :
Mobile Adhoc and Sensor Systems (MASS), 2012 IEEE 9th International Conference on
Conference_Location :
Las Vegas, NV
Print_ISBN :
978-1-4673-2433-5
DOI :
10.1109/MASS.2012.6502534