认知无线电动态频谱接入算法研究
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摘要
随着无线电通信技术的发展,人们对频谱资源的需求也越来越大,但是由于当前采用的频谱资源静态分配的方法导致了频谱资源紧缺和大部分的频谱资源利用率低的矛盾。认知无线电是世界上公认解决该矛盾的革命性的新技术。认知无线用户利用该技术可以智能地感知周围环境,搜索可用频谱资源,并进行动态的频谱接入,从而提高通信系统的容量和频谱利用率。
本文将在部分可观察马尔科夫决策过程的框架下研究认知无线电中的动态频谱接入算法。
首先,本文回顾了认知无线电技术背景,介绍了认知无线的国内外的发展方向和它在各个标准中的标准化过程。
接下来我们根据认知无线电频谱共享技术中的各个步骤,介绍了频谱共享方式的分类。接着从动态专用模型、开放共享模型和分层接入模型三个角度分析了各种接入技术。其中我们重点研究了分层接入技术中是否需要专有控制信道的问题,无专有控制信道分层接入技术是本文研究的重点。
然后我们介绍基于POMDP(Partially Observable Markov Decision Process:部分可观察马尔科夫决策过程)动态频谱接入算法的网络、协议模型以及各个认知无线设备共享信道的方式。我们POMDP的框架下设计了动态频谱接入算法中的检测和接入策略。接着我们采用动态规划的方式求解出了在POMDP框架下的动态接入算法的检测和接入策略。从仿真结果来看,基于POMDP的动态频谱接入算法和随机接入算法相比提高了约25%的频谱接入机会。
最后我们分析了基于POMDP动态频谱接入算法在特殊情况下的一些不足,提出了两种算法改进的方法。一个是采用带权重的POMDP动态频谱接入算法,使得该算法更适合发送短数据包的设备;另一个是采用贪心规则,牺牲一部分算法的性能以降低POMDP的求解,使得更多计算能力较差的认知设备能够实现动态频谱接入技术。之后我们提出了本文中动态频谱接入算法的四个改进方向。
With the development of communication technology, the demand of spectrum is increasing. Due to the spectrum static allocation policy, there is a contradiction between the increasing spectrum demand and low efficiency of most spectrum band. Cognitive radio is worldwide recognized as a creative technology to solve the problem. CR equipments can use CR technology to sense the environment, search for available spectrum resources, and access spectrum dynamically, so that the efficiency of spectrum is improved and the capacity of wireless communication system is increased.
This thesis developed a dynamic spectrum access algorithm under the framework of POMDP (Partially Observable Markov Decision Process).
At first, we retrospect the background of CR, and then introduce the development situation of CR and its standardization process.
Secondly, we introduce the spectrum sharing technology according to its steps, and classify the spectrum sharing technology. Then we analysis the dynamic spectrum access technologies in three views: Dynamic Exclusive Use Model, Open Sharing Model and Hierarchical Access Model. Beside we research the Hierarchical Access Model whether it has a control channel, the Hierarchical Access Model without control channel is our focus technology in this thesis.
Then we introduce the network, protocol and the media share style for the access algorithm based on the POMDP. Under the framework of the PODMP, we design the policy of sensing/accessing. Step forward, we use the dynamic programming solve the problem and get the dynamic sense/access policy. From the result of simulation, the access algorithm can get 25% more access opportunity than the random access policy.
At the end of the thesis, we improve the access algorithm in two scenario. One is for the equipment sending short packages, and we use the weighed PODMP framework to get the new sense/access policy. The other one is for the equipment with low ability of calculation. We use the greedy algorithm to get the suboptimal solution with a little performance loss, but it’s also get 20% more access opportunity than random access policy. At last we bring out four points for future research for dynamic spectrum access in this thesis.
本文将在部分可观察马尔科夫决策过程的框架下研究认知无线电中的动态频谱接入算法。
首先,本文回顾了认知无线电技术背景,介绍了认知无线的国内外的发展方向和它在各个标准中的标准化过程。
接下来我们根据认知无线电频谱共享技术中的各个步骤,介绍了频谱共享方式的分类。接着从动态专用模型、开放共享模型和分层接入模型三个角度分析了各种接入技术。其中我们重点研究了分层接入技术中是否需要专有控制信道的问题,无专有控制信道分层接入技术是本文研究的重点。
然后我们介绍基于POMDP(Partially Observable Markov Decision Process:部分可观察马尔科夫决策过程)动态频谱接入算法的网络、协议模型以及各个认知无线设备共享信道的方式。我们POMDP的框架下设计了动态频谱接入算法中的检测和接入策略。接着我们采用动态规划的方式求解出了在POMDP框架下的动态接入算法的检测和接入策略。从仿真结果来看,基于POMDP的动态频谱接入算法和随机接入算法相比提高了约25%的频谱接入机会。
最后我们分析了基于POMDP动态频谱接入算法在特殊情况下的一些不足,提出了两种算法改进的方法。一个是采用带权重的POMDP动态频谱接入算法,使得该算法更适合发送短数据包的设备;另一个是采用贪心规则,牺牲一部分算法的性能以降低POMDP的求解,使得更多计算能力较差的认知设备能够实现动态频谱接入技术。之后我们提出了本文中动态频谱接入算法的四个改进方向。
With the development of communication technology, the demand of spectrum is increasing. Due to the spectrum static allocation policy, there is a contradiction between the increasing spectrum demand and low efficiency of most spectrum band. Cognitive radio is worldwide recognized as a creative technology to solve the problem. CR equipments can use CR technology to sense the environment, search for available spectrum resources, and access spectrum dynamically, so that the efficiency of spectrum is improved and the capacity of wireless communication system is increased.
This thesis developed a dynamic spectrum access algorithm under the framework of POMDP (Partially Observable Markov Decision Process).
At first, we retrospect the background of CR, and then introduce the development situation of CR and its standardization process.
Secondly, we introduce the spectrum sharing technology according to its steps, and classify the spectrum sharing technology. Then we analysis the dynamic spectrum access technologies in three views: Dynamic Exclusive Use Model, Open Sharing Model and Hierarchical Access Model. Beside we research the Hierarchical Access Model whether it has a control channel, the Hierarchical Access Model without control channel is our focus technology in this thesis.
Then we introduce the network, protocol and the media share style for the access algorithm based on the POMDP. Under the framework of the PODMP, we design the policy of sensing/accessing. Step forward, we use the dynamic programming solve the problem and get the dynamic sense/access policy. From the result of simulation, the access algorithm can get 25% more access opportunity than the random access policy.
At the end of the thesis, we improve the access algorithm in two scenario. One is for the equipment sending short packages, and we use the weighed PODMP framework to get the new sense/access policy. The other one is for the equipment with low ability of calculation. We use the greedy algorithm to get the suboptimal solution with a little performance loss, but it’s also get 20% more access opportunity than random access policy. At last we bring out four points for future research for dynamic spectrum access in this thesis.
引文
1 Danijela Cabric. Implementation Issues in Spectrum Sensing for Cognitive Radio. Signals, Systems and Computers, 2004. Conference Record of the Thirty-Eighth Asilomar Conference, 2004, 1(1): 772~776
2 Ian F. Akyildiz. Won-Yeol Lee. Mehmet C. Vuran. Shantidev Mohanty. NeXt generation/dynamic spectrum access/cognitive radio wireless networks: A survey. Computer Networks, 2006(50): 2127~2159
3 W. Krenik, A. Batra. Cognitive Radio Techniques for Wide Area Networks. Design Automation Conference, California,USA. June 2005: 409~412
4 J. Mitola, et al. Cognitive Radio: Making Software Radios More Personal. IEEE Pers. Commun.. 1999, 6 (4): 13~18
5 J. Mitola, G. Maguire. Cognitive Radio: Making Software Radio more Personal. IEEE Personal Communication Magazine. 1999, 6(4): 13-18
6 Simon Haykin. Cognitive Radio: Brain-Empowered Wireless Communications. IEEE Journal on Selected Areas in Communications. 2005, 23(2): 201~220
7 T. A. Weiss, F. K. Jondral. Spectrum pooling: an Innovative Strategy for the Enhancement of Spectrum Efficiency. IEEE Radio Communications. 2004, 22(3): 8-14
8 P. Leaves, D. Grandblaise, D. Bourse, et al. Dynamic Spectrum Allocation in Composite Reconfigurable Wireless Networks. IEEE Communications Magzine. 2004, 22(5): 72~81
9 R. W. Broderson, D. Cabriv, I. D. O'Donnell, et al. Spectrum Sharing Radios, The First IEEE International Symposium on New Frontiers in Dynamic Spectrum Access Networks (DySPAN). 2005: 371~378
10 M. M. Buddhikot, P. Kolodzy, S. Miller, et al. DTMSTTMNet: New Directions in Wireless Networking Using Coordinated Dynamica Spectrum Access. WoWMOM 2005. 2005: 78~85
11 William Krenik, Anuj Batra. Cognitive Radio Techniques for Wide Area Networks. Texas Instruments Incorporated. 2005, 1(26): 409~412
12叶佩军,安建平.认知无线电在未来多媒体移动通信中的应用.电讯技术. 2004, (2): 25~29
13 D. Maldonado, Le Bin, A. Hugine, T.W. Rondeau, C.W. Bostian. Cognitive Radio Applications to Dynamic Spectrum Allocation: A Discussion and An Illustrative Example. 2005 First IEEE International Symposium on New Frontiers in Dynamic Spectrum Access Networks. 2005: 597~600
14田峰,程世伦,杨震.无线区域网和认知无线电技术.中兴通讯技术. 2006, 12(4): 61~64
15 Xiangpeng Jing, Siun~Chuon Mau, D. Raychaudhuri, Robert Matyas. Reactive Cognitive Radio Algorithms for Co-Existence between IEEE 802.11b and 802.16a Networks. IEEE GLOBECOM 2005 proceedings. 2005:2465~2469
16周小飞,张宏纲.认知无线电原理及应用.北京邮电大学出版社. 2007: 17~38, 99~132
17张亮,赵林靖,胡婧,韩斐.基于认知无线电技术的802.22标准.无线电工程. 2007, 1(37): 9~20
18 IEEE P1900 Working Group. www.scc41.org
19 IEEE 802.16’s License-Exempt (LE) Task Group. http://www.ieee802.org/16/
20 IEEE P802.11-Task Group Y-Meeting Update: Status of project IEEE 802.11y. http://grouper.ieee.org/groups/802
21 William Krenik, Anuj Batra. Cognitive Radio Techniques for Wide Area Networks. Texas Instruments Incorporated. 2005, 26(1): 409~412
22 I.F. Akyildiz, X. Wang, W. Wang. Wireless mesh networks: a survey. Computer Networks Journal. 2005, 47 (4): 445~487
23 Danijela Cabric. Implementation Issues in Spectrum Sensing for Cognitive Radios. Signals Systems and Computers. Conference Record of the Thirty-Eighth Asilomar Conference. 2004, 1(1): 772~776
24 H. Urkowitz. Energy Detection of Unknown Deterministic Signals. Proceedings of the IEEE. April 1967, 4(55): 337~380
25 Brik V, Rozner E, Banarjee S, Bahl P. DSAP:a protocol for coordinated spectrum access. IEEE DySPAN 2005,9: 611~614
26 Zekavat S, Li X. User-central wireless system: ultimate dynamic channel allocation. IEEE DySPAN 2005 (9): 82~87
27 Peng C, Zheng H, Zhao B Y. Utilization and fairness in spectrum assigment for opportunistic spectrum access. ACM Mobile Networks and Application,2006,4:1007~1029
28 H Zheng, C Peng Collaboration and fairness in opportunistic spectrum access. IEEE ICC 2005, 2005, 5(5):3132~3136
29 N Nie, C Comaniciu. Adaptive channel allocation spectrum etiquette for cognitive radio networks. Mobile Networks and Applications, 2006.
30 Zhao Q, Sadler B M. A Survey of Dynamic Spectrum Access. Signal Processing Magazine, IEEE, 2007, 24:79~89.
31 Raman C, Yates R, Mandayam N. Scheduling variable rate links via a spectrum server, 2005, 9: 110~118
32 De A, Vany A D, Ca T B. Implementing a Market-Based Spectrum Policy. Journal of Law &Economics, 1998, 41
33 L. W.“Propertyzing”the electromagnetic spectrum: why it is important and how to begin. Media Law and Policy, 2000, 19: 1~42
34 Raman C, Yates R, Mandayam N. Scheduling variable rate links via a spectrum server. 2005,9 : 110~118
35 Zhang Z, Chan S C, Cheng H. Robust adaptive channel estimation of OFDM systems in time-varying narrowband interference. 2005,5: 1722~1725
36 Hang Su, Xi Zhang. Opportunistic MAC Protocols for Cognitive Radio Based Wireless Networks. 2007,9: 363~782
37 A.V.Adamis, Prof.Philip Constantinou.Performance study of CSMA/CA over spectrum pooling environment for cognitive radios.IEEE Wireless and Mobile Computing,Networking and Communications. 2007: 31~31
38 Y. Chen, Q. Zhao, and A. Swami,“Proof of the separation principle for opportunistic spectrum access,”Technical report, University of California at Davis, 2006.http://www.ece.ucdavis.edu/ qzhao/Report.html
39 R.Smallwood, E. Sondik. The optimal control of partially observable Markov processes over a finite horizon. Operation Research, 1971: 1071~1088
40 T Javidi, B Krishnamachari, Q Zhao, M Liu Optimality of Myopic Sensing in Multi-Channel Opportunistic Access IEEE International Conference on Communications ICC, 2008: 200~207
41 Q Zhao, B Krishnamachari. Structure and optimality of myopic sensing for opportunistic spectrum access. IEEE International Conference on Communications ICC, 2007: 217~222
42 J. Juncheng, Z. Qian and S. Xuemin. HC-MAC: A hardware-constrainedcognitive MAC for e?cient spectrum management,”IEEE Journal on Selected Areas in Communications. 2008,26: 106~117
43 N. B. Chang and M. Liu,“Optimal channel probing and transmission scheduling for opportunistic spectrum access,”Proc. 13th ACM Annual International Conference on Mobile Computing and Networking (MobiCom’07), 2007,9 : 27~38
44 A. Sabharwal, A. Khoshnevis, E. Knightly. Opportunistic spectral usage:Bounds and a multi-band CSMA/CA protocol. IEEE/ACM Transaction on Networking, 2007,15: 533~545
45 S Krishnamurthy, M Thoppian, S Venkatesan. Control channel based MAC-layer configuration, routing and situation awareness for cognitive radio networks. IEEE Military Communications Conference ICC, 2005: 1~6
2 Ian F. Akyildiz. Won-Yeol Lee. Mehmet C. Vuran. Shantidev Mohanty. NeXt generation/dynamic spectrum access/cognitive radio wireless networks: A survey. Computer Networks, 2006(50): 2127~2159
3 W. Krenik, A. Batra. Cognitive Radio Techniques for Wide Area Networks. Design Automation Conference, California,USA. June 2005: 409~412
4 J. Mitola, et al. Cognitive Radio: Making Software Radios More Personal. IEEE Pers. Commun.. 1999, 6 (4): 13~18
5 J. Mitola, G. Maguire. Cognitive Radio: Making Software Radio more Personal. IEEE Personal Communication Magazine. 1999, 6(4): 13-18
6 Simon Haykin. Cognitive Radio: Brain-Empowered Wireless Communications. IEEE Journal on Selected Areas in Communications. 2005, 23(2): 201~220
7 T. A. Weiss, F. K. Jondral. Spectrum pooling: an Innovative Strategy for the Enhancement of Spectrum Efficiency. IEEE Radio Communications. 2004, 22(3): 8-14
8 P. Leaves, D. Grandblaise, D. Bourse, et al. Dynamic Spectrum Allocation in Composite Reconfigurable Wireless Networks. IEEE Communications Magzine. 2004, 22(5): 72~81
9 R. W. Broderson, D. Cabriv, I. D. O'Donnell, et al. Spectrum Sharing Radios, The First IEEE International Symposium on New Frontiers in Dynamic Spectrum Access Networks (DySPAN). 2005: 371~378
10 M. M. Buddhikot, P. Kolodzy, S. Miller, et al. DTMSTTMNet: New Directions in Wireless Networking Using Coordinated Dynamica Spectrum Access. WoWMOM 2005. 2005: 78~85
11 William Krenik, Anuj Batra. Cognitive Radio Techniques for Wide Area Networks. Texas Instruments Incorporated. 2005, 1(26): 409~412
12叶佩军,安建平.认知无线电在未来多媒体移动通信中的应用.电讯技术. 2004, (2): 25~29
13 D. Maldonado, Le Bin, A. Hugine, T.W. Rondeau, C.W. Bostian. Cognitive Radio Applications to Dynamic Spectrum Allocation: A Discussion and An Illustrative Example. 2005 First IEEE International Symposium on New Frontiers in Dynamic Spectrum Access Networks. 2005: 597~600
14田峰,程世伦,杨震.无线区域网和认知无线电技术.中兴通讯技术. 2006, 12(4): 61~64
15 Xiangpeng Jing, Siun~Chuon Mau, D. Raychaudhuri, Robert Matyas. Reactive Cognitive Radio Algorithms for Co-Existence between IEEE 802.11b and 802.16a Networks. IEEE GLOBECOM 2005 proceedings. 2005:2465~2469
16周小飞,张宏纲.认知无线电原理及应用.北京邮电大学出版社. 2007: 17~38, 99~132
17张亮,赵林靖,胡婧,韩斐.基于认知无线电技术的802.22标准.无线电工程. 2007, 1(37): 9~20
18 IEEE P1900 Working Group. www.scc41.org
19 IEEE 802.16’s License-Exempt (LE) Task Group. http://www.ieee802.org/16/
20 IEEE P802.11-Task Group Y-Meeting Update: Status of project IEEE 802.11y. http://grouper.ieee.org/groups/802
21 William Krenik, Anuj Batra. Cognitive Radio Techniques for Wide Area Networks. Texas Instruments Incorporated. 2005, 26(1): 409~412
22 I.F. Akyildiz, X. Wang, W. Wang. Wireless mesh networks: a survey. Computer Networks Journal. 2005, 47 (4): 445~487
23 Danijela Cabric. Implementation Issues in Spectrum Sensing for Cognitive Radios. Signals Systems and Computers. Conference Record of the Thirty-Eighth Asilomar Conference. 2004, 1(1): 772~776
24 H. Urkowitz. Energy Detection of Unknown Deterministic Signals. Proceedings of the IEEE. April 1967, 4(55): 337~380
25 Brik V, Rozner E, Banarjee S, Bahl P. DSAP:a protocol for coordinated spectrum access. IEEE DySPAN 2005,9: 611~614
26 Zekavat S, Li X. User-central wireless system: ultimate dynamic channel allocation. IEEE DySPAN 2005 (9): 82~87
27 Peng C, Zheng H, Zhao B Y. Utilization and fairness in spectrum assigment for opportunistic spectrum access. ACM Mobile Networks and Application,2006,4:1007~1029
28 H Zheng, C Peng Collaboration and fairness in opportunistic spectrum access. IEEE ICC 2005, 2005, 5(5):3132~3136
29 N Nie, C Comaniciu. Adaptive channel allocation spectrum etiquette for cognitive radio networks. Mobile Networks and Applications, 2006.
30 Zhao Q, Sadler B M. A Survey of Dynamic Spectrum Access. Signal Processing Magazine, IEEE, 2007, 24:79~89.
31 Raman C, Yates R, Mandayam N. Scheduling variable rate links via a spectrum server, 2005, 9: 110~118
32 De A, Vany A D, Ca T B. Implementing a Market-Based Spectrum Policy. Journal of Law &Economics, 1998, 41
33 L. W.“Propertyzing”the electromagnetic spectrum: why it is important and how to begin. Media Law and Policy, 2000, 19: 1~42
34 Raman C, Yates R, Mandayam N. Scheduling variable rate links via a spectrum server. 2005,9 : 110~118
35 Zhang Z, Chan S C, Cheng H. Robust adaptive channel estimation of OFDM systems in time-varying narrowband interference. 2005,5: 1722~1725
36 Hang Su, Xi Zhang. Opportunistic MAC Protocols for Cognitive Radio Based Wireless Networks. 2007,9: 363~782
37 A.V.Adamis, Prof.Philip Constantinou.Performance study of CSMA/CA over spectrum pooling environment for cognitive radios.IEEE Wireless and Mobile Computing,Networking and Communications. 2007: 31~31
38 Y. Chen, Q. Zhao, and A. Swami,“Proof of the separation principle for opportunistic spectrum access,”Technical report, University of California at Davis, 2006.http://www.ece.ucdavis.edu/ qzhao/Report.html
39 R.Smallwood, E. Sondik. The optimal control of partially observable Markov processes over a finite horizon. Operation Research, 1971: 1071~1088
40 T Javidi, B Krishnamachari, Q Zhao, M Liu Optimality of Myopic Sensing in Multi-Channel Opportunistic Access IEEE International Conference on Communications ICC, 2008: 200~207
41 Q Zhao, B Krishnamachari. Structure and optimality of myopic sensing for opportunistic spectrum access. IEEE International Conference on Communications ICC, 2007: 217~222
42 J. Juncheng, Z. Qian and S. Xuemin. HC-MAC: A hardware-constrainedcognitive MAC for e?cient spectrum management,”IEEE Journal on Selected Areas in Communications. 2008,26: 106~117
43 N. B. Chang and M. Liu,“Optimal channel probing and transmission scheduling for opportunistic spectrum access,”Proc. 13th ACM Annual International Conference on Mobile Computing and Networking (MobiCom’07), 2007,9 : 27~38
44 A. Sabharwal, A. Khoshnevis, E. Knightly. Opportunistic spectral usage:Bounds and a multi-band CSMA/CA protocol. IEEE/ACM Transaction on Networking, 2007,15: 533~545
45 S Krishnamurthy, M Thoppian, S Venkatesan. Control channel based MAC-layer configuration, routing and situation awareness for cognitive radio networks. IEEE Military Communications Conference ICC, 2005: 1~6