Cognitive Software-Radio Enabled Fair Spectrum Access in Open Spectrum
Systems
Utilization and Fairness in Spectrum Assignment for
Opportunistic Spectrum Access Chunyi Peng, Haitao Zheng, Ben Y. Zhao submitted
The Open Spectrum approach to spectrum access can achieve near-optimal
utilization by allowing devices to sense and utilize available spectrum
opportunistically. However, a naive distributed spectrum assignment can
lead to significant interference between devices. In this paper, we define
a general framework that defines the spectrum access problem for several
definitions of overall system utility. By reducing the allocation problem
to a variant of the graph coloring problem, we show that the global
optimization problem is NP-hard, and provide a general approximation
methodology through vertex labeling. We examine both a centralized
strategy, where a central server calculates an allocation assignment based on
global knowledge, and a distributed approach, where devices collaborate to
negotiate local channel assignments towards global optimization. Our
experimental results show that our allocation algorithms can dramatically
reduce interference and improve throughput (as much as 800\%). Further
simulations show that our distributed algorithms generate allocation
assignments similar in quality to our centralized algorithms using global
knowledge, while incurring substantially less computational complexity in
the process.
