We consider a collision-sensitive secondary system that intends to opportunistically aggregate and utilize spectrum of a primary system to achieve higher data rates. In such opportunistic spectrum access, secondary transmission can collide with primary transmission. When the secondary system aggregates more channels for data transmission, more frequent collisions may occur, limiting the performance obtained by the opportunistic spectrum aggregation. In this context, dynamic spectrum aggregation problem is formulated to maximize the ergodic channel capacity under the constraint of collision tolerable level. To solve the problem, we develop the optimal spectrum aggregation approach, deriving closed-form expressions for the collision probability in terms of primary user traffic load, secondary user transmission interval, and the random number of sub-channels aggregated. Our results show that aggregating only a subset of sub-channels will be a better choice, depending on the ratio of collision sensitivity requirement to the primary user traffic.
|Title of host publication||Proceedings of the 2014 9th International Conference on Cognitive Radio Oriented Wireless Networks and Communications: CROWNCOM 2014|
|Editors||Matti Latva-aho, Savo Glisic, Allen MacKenzie, Alhussein Abouzeid, Olav Tirkkonen, Markku Juntti, Juha Röning, Hiroshi Harada|
|Place of Publication||Oulu, Finland|
|Publisher||Institute of Electrical and Electronics Engineers (IEEE)|
|Publication status||Published - 23 Jul 2014|