The Research of Greedy Algorithm on Cognitive Radio

Greedy algorithm for which situation of users´ number more than free channel´s number gives tacit consent to each user could receive one sub-channel. This is very different from virtual situation. For this reason, this text has improved the greedy algorithm. In allocation progress of spectrum resources, the conflict of secondary users and authorized users on time domain has to be considered, and also the competition between secondary users on frequency domain. On time domain, utilizing probability to describe the influence which conflict bring to systematic total benefit. On frequency domain, using decreased number of channels to characterize the competitive relationship between each secondary user. The improved greedy algorithm has better systematic total throughput and property of competitive auction system transmittal data quantity for each time. It is able to tackle the problem of unreasonable allocation for resource management. And then, give secondary users more effective and more possibility of spectrum access, improved the situation of spectrum resources deficiency.