Opportunistic Channel Selection by Cognitive Radios Under Imperfect Observations and Limited Memory: A Repeated Game Model

Speaker : Zaheer Khan
L'Université d'Oulu en Finlande
Date: 20/03/2014
Time: 2:00 pm - 3:00 pm
Location: LINCS Meeting Room 40


To help mitigate the critical stress on spectrum resources spurred by the more powerful and the more capable smart devices, a recent presidential advisory committee report and also a FCC report recommend the use of spectrum sharing technologies. One such technology addressed in these reports is cognitive radio (CR), in which a network entity is able to adapt intelligently to the environment through observation, exploration and learning. In this talk, we discuss the problem of coexistence, competition and  fairness among autonomous cognitive Radios (CRs) in multiple potentially available channels that may be non-homogeneous in terms of  primary user (PU) occupancy. Moreover, the real spectrum occupancy data collected at RWTH Aachen confirms  that the spectrum resources are in general non-homogeneous in terms of PU occupancy.   We present a model in which a CR that is able to adapt to the environment through observation and exploration is limited in two ways. First, as in practical CR networks, CRs have imperfect observations (such as due to sensing and channel errors) of their environment. Second, CRs have imperfect memory due to limitations in computational capabilities. For efficient opportunistic channel selection, we discuss efficient strategies and utilize the framework of repeated games (with imperfect observations and memory) to analyze their stability in the presence of selfish deviations.