PROJECT TITLE :

One Step Beyond Myopic Probing Policy: A Heuristic Lookahead Policy for Multi-Channel Opportunistic Access

ABSTRACT:

During this paper, we consider the probing order and stopping downside arising from the identification of spectrum holes in multi-channel cognitive radio networks, in that a secondary user (SU) seeks to maximise the chance of finding an accessible channel whereas minimizing the related probing value at intervals a long time horizon. This problem can be casted into a restless multi-armed bandit drawback, that is proved to be PSPACE-laborious. The key point of this problem is that the trade-off between exploitation, in that the SU stops probing once an accessible channel is identified, and exploration, in that the SU continues to probe new channels even when identifying an obtainable channel so as to find out the system state to scale back probing price in the longer term. To strike a desirable balance between the 2 conflicting objectives, we have a tendency to develop a heuristic channel probing policy, termed the v-step lookahead policy, in that the SU makes its decision based on the prediction of system state among the future v steps, with v being a tunable parameter. We have a tendency to conduct an analytical study on the structure of the proposed v-step lookahead policy and demonstrate how the policy can be implemented with linear complexity with respect to the amount of channels in the system via an in depth analysis on the 1-step lookahead policy. Numerical experiments between the v-step lookahead policy and myopic probing policy on two representative network situations demonstrate the effectiveness of the proposed v-step lookahead policy.