A new adaptive sensing scheme for low SNR and random arrival of PU environment

作者：Xie Xianzhong^*; Song Ting; Ma Bin; Hu Xiaofeng

来源：Journal of Communications, 2014, 9(3): 262-270.

DOI：10.12720/jcm.9.3.262-270

• Cognitive radio network
• Collaborative detection
• Decision-making algorithms
• Decision-making systems
• Low SNR
• POMDP
• Spectrum sensing
• Transmission periods

Cognitive radio (CR) networks facing with difficulties caused by the low SNR environment and the random arrival of primary users (PUs) application traffic. The existing studies focus on the unilateral processing on weak PU signal or random departure/arrival of PU problems. In this paper, we propose an adaptive sensing scheme which is applicable under certain adverse conditions by jointly optimize sensing and transmission period. At first the adaptive sensing state model is established. On this basis, secondary users (SUs) perform collaborative detection in the sensing period and an optimal sensing duration is determined to obtain adaptability and detection reliability. At the end of each period, a decision-making system predicts PU's activity based on the previous observations and adaptively chooses whether to perform spectrum sensing, data transmission or channel switching. Both the impact of non-ideal sensing and the imperfect ACK/NACK feedback are being fully considered when designing the decision-making algorithm. Numerical results show that our optimal scheme significantly increases SU utility while avoiding interference to PU in the adverse environment, and it reduces detection difficulty and computational complexity.

• 出版日期2014