概率反馈动态频谱分配策略及性能分析

doi:10.11959/j.issn.1000-436x.2015170

摘要/Abstract

摘要：

为了折衷认知用户吞吐量与平均时延，并适应多种网络业务需求，在认知无线电网络中引入概率反馈机制和能量检测阈值，提出一种新的动态频谱分配策略。针对认知用户的非理想感知结果，建立一种2类用户可能相互干扰的优先级排队模型，并构造状态转移概率矩阵。采用矩阵几何解方法求出系统的稳态分布，给出信道利用率、认知用户吞吐量、认知用户平均延迟及授权用户干扰率等性能指标的表达式。通过数值实验和系统仿真验证所提动态频谱分配策略性的有效性，并给出能量检测阈值的优化设置方案。

关键词: 认知无线电网络, 动态频谱分配策略, 概率反馈, 非理想感知, 优先级排队模型

Abstract:

By introducing probabilistic feedback mechanism and energy detection threshold to cognitive radio networks,a novel dynamic spectrum allocation strategy is proposed to trade off the throughput and average delay of secondary users,as well as meet various network requirements.Considering the imperfect sensing results of secondary users,a kind of priority queueing model is established,in which two classes of users may interfere with each other,then the state transition probability matrix is constructed.Employing the method of matrix-geometric solution,the stationary distribution of system model is derived.Accordingly,the expressions for the performance measures in terms of channel utilization,throughput of secondary users,average delay of secondary users and interference ratio of primary users are given.With numerical experiments and system simulations,the effectiveness of the proposed dynamic spectrum allocation strategy is verified.Finally,the optimal design of energy detection threshold is provided.

Key words: cognitive radio networks, dynamic spectrum allocation strategy, probabilistic feedback, imperfect sensing, priority queueing model

金顺福,葛世英,霍占强. 概率反馈动态频谱分配策略及性能分析[J]. 通信学报, 2015, 36(7): 10-17.

Shun-fu JIN,Shi-ying GE,Zhan-qiang HUO. Dynamic spectrum allocation strategy with probabilistic feedback mechanism and performance analysis[J]. Journal on Communications, 2015, 36(7): 10-17.

图/表 8

图1

表1

图2

图3

表2

表3

图4

表4

参考文献 12

[1]	ZHAO Q , SADLER B M . A survey of dynamic spectrum access[A]. International Conference on Acoustics,Speech and Signal Processing[C]. Honolulu,USA, 2007. 79-89.
[2]	GEIRHOFER S , TONG L , SADLER B M . Cognitive medium access:constraining interference based on experimental models[J]. IEEE Journal on Selected Areas in Communications, 2008,26(1): 95-105.
[3]	LIANG Y C , CHEN K C , LI G Y , et al. Cognitive radio networking and communications:an overview[J]. IEEE Transactions on Vehicular Technology, 2011,60(7): 3386-3407.
[4]	WANG B , LIU K J R . Advances in cognitive radio networks:a survey[J]. IEEE Journal on Selected Topics in Signal Processing, 2011,5(1): 5-23.
[5]	ZHANG Y , JIANG T , ZHANG L , et al. Analysis on the transmission delay of priority-based secondary users in cognitive radio networks[A]. International Conference on Wireless Communications and Signal Processing[C]. Hangzhou,China, 2013. 1-6.
[6]	ASHOUR M , EL-SHERIF A A , ELBATT T , et al. Cognitive radio networks with probabilistic relaying:stable throughput and delay tradeoffs[J]. arXiv preprint arXiv:1404.6112, 2014.
[7]	WANG S , ZHANG J , TONG L . Delay analysis for cognitive radio networks with random access:a fluid queue view[A]. International Conference on Computer Communications[C]. Zürich,Switzerland, 2010. 1-9.
[8]	郭彩丽, 冯存燕, 曾志民 . 认知无线电网络技术及应用[M]. 北京: 电子工业出版社, 2011. 38-40. GUO C L , FENG C Y , ZENG Z M . Cognitive Radio Network Technologies and Applications[M]. Beijing: Publishing House of Electronics IndustryPress, 2010 38-40.
[9]	BHOWMICK A , DAS M K , BISWAS J , et al. Throughput optimization with cooperative spectrum sensing in cognitive radio network[A]. International Advance Computing Conference[C]. Gurgaon,India, 2014. 329-332.
[10]	张晶, 陆音, 高西奇等. 主用户干扰约束下的机会频谱接入感知传输时隙优化调度[J]. 通信学报, 2013,34(12):42-48. ZHANG J , LU Y , GAO X Q , et al. Sensing-then-transmission slot scheduling optimization for opportunistic spectrum access under the interference constraint of primary users[J]. Journal on Communications, 2013,34(12): 42-48.
[11]	LIANG Y C , ZENG Y , PEH E C Y , et al. Sensing-throughput tradeoff for cognitive radio networks[J]. IEEE Transactions on Wireless Communications, 2008,7(4): 1326-1337.
[12]	ALFA A S . Queueing Theory for Telecommunications[M]. New York: Springer Science+Business Media,LLCPress, 2010. 118-121.

参数名称	参数值
时隙/ms	1
物理层数据速率/Mbit·s^?1	11
认知用户数据分组达到率	0.1
认知用户数据分组大小的均值/byte	1 760
认知用户数量/个	3×10⁶
授权用户数据分组到达率	0.1
授权用户数据分组大小的均值/byte	2 010
授权用户数量/个	3×10⁶
反馈概率	0～1.0
能量检测阈值	1.0～5.0
仿真时间/时隙	3×10⁶

检测阈值τ	反馈概率q=0		反馈概率q=0.25		反馈概率q=0.5		反馈概率q=0.75		反馈概率q=1
检测阈值τ	理论值	仿真值	理论值	仿真值	理论值	仿真值	理论值	仿真值	理论值	仿真值
1.0	3.370 7	3.365 3	3.452 9	3.451 8	3.539 2	3.558 9	3.630 2	3.631 4	3.726 5	3.718 6
1.5	2.270 2	2.273 8	2.312 1	2.314 8	2.355 0	2.370 0	2.399 0	2.400 1	2.444 1	2.444 3
2.0	1.829 5	1.828 2	1.854 1	1.859 9	1.879 0	1.883 8	1.904 2	1.902 7	1.929 8	1.927 0
2.5	1.644 5	1.647 7	1.660 7	1.660 1	1.676 9	1.681 9	1.693 2	1.694 2	1.709 7	1.708 2
3.0	1.570 1	1.573 1	1.582 4	1.581 8	1.594 7	1.594 7	1.607 1	1.606 1	1.619 5	1.616 5
3.5	1.542 7	1.544 6	1.553 4	1.551 8	1.564 1	1.563 5	1.574 9	1.571 8	1.585 6	1.584 1
4.0	1.532 8	1.534 9	1.542 8	1.540 0	1.552 8	1.552 2	1.562 9	1.558 2	1.572 9	1.571 4
4.5	1.528 0	1.528 7	1.537 6	1.533 2	1.547 2	1.546 0	1.556 8	1.554 1	1.566 4	1.563 8
5.0	1.524 3	1.523 8	1.533 5	1.531 7	1.542 6	1.542 6	1.551 8	1.551 6	1.561 1	1.557 7

检测阈值τ	反馈概率q=0		反馈概率q=0.25		反馈概率q=0.5		反馈概率q=0.75		反馈概率q=1
检测阈值τ	理论值	仿真值	理论值	仿真值	理论值	仿真值	理论值	仿真值	理论值	仿真值
1.0	0.010 3	0.010 2	0.010 6	0.010 8	0.010 9	0.010 9	0.011 3	0.011 6	0.011 7	0.011 8
1.5	0.010 6	0.010 7	0.010 8	0.011 2	0.011 1	0.011 3	0.011 3	0.011 5	0.011 6	0.012 0
2.0	0.011 9	0.011 5	0.012 1	0.012 2	0.012 4	0.012 3	0.012 6	0.012 8	0.012 8	0.013 4
2.5	0.014 2	0.013 9	0.014 4	0.014 5	0.014 6	0.014 5	0.014 8	0.014 6	0.015 0	0.015 1
3.0	0.017 3	0.017 5	0.017 5	0.017 7	0.017 8	0.017 9	0.018 0	0.017 9	0.018 2	0.018 0
3.5	0.021 2	0.021 3	0.021 5	0.021 7	0.021 8	0.021 7	0.022 0	0.021 9	0.022 3	0.022 5
4.0	0.025 9	0.026 3	0.026 2	0.026 5	0.026 5	0.026 7	0.026 8	0.026 8	0.027 1	0.027 6
4.5	0.031 2	0.031 5	0.031 5	0.031 6	0.031 9	0.032 1	0.032 2	0.032 4	0.032 6	0.032 5
5.0	0.037 1	0.037 1	0.037 5	0.037 1	0.037 9	0.037 8	0.038 3	0.038 1	0.038 7	0.039 5

反馈概率q	系统最大收益R_max	最优检测阈值τ^*
0	3.647	2.85
0.25	3.668	2.80
0.50	3.691	2.70
0.75	3.715	2.65
1.00	3.741	2.55