Opportunistic Spectrum Access in Multi-User Multi-Channel Cognitive Radio Networks
With the advent of cognitive radio technology, opportunistic spectrum access has the potential to mitigate spectrum scarcity by letting users sense and utilize unused portions of licensed spectrum opportunistically without adverse impact on the primary licensees (licensed spectrum owner). The authors consider the problem of how multiple secondary users should maximize their total throughput in a multi-channel sensing-based opportunistic spectrum access network under various traffic conditions. They developed two dynamic spectrum access algorithms (Hungarian and Greedy) which allow secondary users (unlicensed opportunistic users) to access spectrum based on non-cooperative independent decisions. Both algorithms allow the secondary users to seek independent spectrum opportunities without cooperation with the objective of minimizing collisions among secondary users and maximizing the spectrum utility.