Throughput Maximization Based on Optimal Access Probabilities in Cognitive Radio System

• 作者: Lian Zhao Mohamed Elalem
• 来源期刊: 通讯与网络(英文)
• 学科: 工学
• 关键词: COGNITIVE RADIO ACCESS PROBABILITY Underlay/Overlay SCHEMES Marckov Model
• 年，卷（期）: txywlyw_2013,（3）
• 页码范围: 204-210
• 页数: 7页
• 分类号: TN92

摘要

Well-established fact shows that the fixed spectrum allocation policy conveys to the low spectrum utilization. The cognitive radio technique promises to improve the low efficiency. This paper proposes an optimized access strategy combining overlay scheme and underlay scheme for the cognitive radio. We model the service state of the system as a continuous-time Markov model. Based on the service state, the overlay manner or/and the underlay manner is/are used by the secondary users. When the primary user is not transmitting and only one secondary user has the requirement to transmit, the secondary system adopts the overlay scheme. When the primary user is transmitting and the secondary users want to transmit simultaneously, an underlay scheme with an access probability is adopted. We obtain the optimal access probability in a closed form which maximizes the overall system throughput.