Reading time : Cognitive Radio : Theory and Application
Paper comes from : IEEE Journal on Selected Areas in Communications, Special Issue on “Cognitive Radio: Theory and Application”, vol. 26, no. 1, January 2008.
Radio spectrum resource is of fundamental importance in wireless communications. Nowadays, the access to radio spectrum is largely based on fixed spectrum allocation principle.With the deployment of more wireless applications/services,most of the available spectrum has been well allocated, thus many countries are facing the problem of spectrum scarcity. On the other hand, measurement studies have revealed that most of the allocated spectrum experiences low utilization efficiency. These two facts motivate the introduction of dynamic spectrum access, which allows secondary users to reuse/share the same radio spectrum originally allocated to the primary(licensed) users.
PS: Radio spectrum is not enough for our life and most of the allocated spectrum experiences low utilization efficiency. So we need use CR to solve these problems.
Cognitive radio is the enabling technology for dynamic spectrum access. The essential components in a cognitive radio system include spectrum sensing, cognitive medium access control and cognitive networking. The research on cognitive radio technology however involves interdisciplinary effort from various technical societies, including, e.g., signal processing,information theory, communications engineering, as well as cooperation/game theory societies. This Special Issue focuses on the state-of-art research results on cognitive radio and its applications. We have received a total of 54 submissions, and after a careful review process to asses the quality of the papers, we accepted 17 papers in this Special Issue, covering spectrum sensing, physical layer aspects, medium access control (MAC), networking and game theory for cognitive radio networks.
PS: CR components : The essential components in a cognitive radio system include spectrum sensing, cognitive medium access control and cognitive networking.Next are some paper about reserch of CR recently.
The first set of three papers is related to spectrum sensing in cognitive radio networks.
In “Spatiotemporal Sensing in Cognitive Radio Networks,”Ganesan, Li, Bing, and Li exploit the spatial diversity in multiuser networks to improve the spectrum sensing capabilities of centralized cognitive radio networks.
In “Cyclostationary Signatures in Practical Cognitive Radio Applications,” Sutton, Nolan, and Doyle explore the cyclostationary signatures of the communications signals for signal detection, network identification and rendezvous and discuss these in the context of dynamic spectrum access.
In “Defense against Primary User Emulation Attacks in Cognitive Radio Networks,” Chen, Park, and Reed consider the security aspects of spectrum sensing in cognitive radio networks where a secondary user may transmit signals whose characteristics emulate those of incumbent signals; and in order to counter this threat, they propose a transmitter verification scheme, which uses both signal characteristics and location of the signal transmitter to verify the presence of primary users.
The second set of four papers deals with physical layer aspects of cognitive radio.
In “Joint Beamforming and Power Allocation for Multiple Access Channels in Cognitive Radio Networks,” Zhang,Liang, and Xin study the problems of maximizing the throughput or ensuring the Quality-of Service (QoS) of the secondary users, yet to maintain the QoS of the primary user; they consider single-input-multiple-output multiple access channel and propose joint beamforming and power allocation schemes to solve these problems.
In “Frame Synchronization for Cognitive Radios with Variable-Length Packets,” Suwansantisuk, Chiani, and Win study the problem of synchronizing the variable-length frames in cognitive radio systems; they propose two performance metrics for frame synchronization.
In “Cognitive Radio Based Multi-User Resource Allocation in Mobile Ad Hoc Networks using Multi-Carrier CDMA Modulation,” Qu, Milstein, and Vaman propose a cognitive radio based multi-user resource allocation framework for mobile ad hoc networks using multi-carrier DS CDMA modulation over a frequency-selective fading channel.
In “Low-Complexity Adaptive Transmission for Cognitive Radios in Dynamic Spectrum Access Networks,” Pursley and Royster IV propose an adaptive transmission protocol for the use in cognitive radio networks where the links have unknown and possibly time-varying propagation losses.
The third set of three papers deals with the MAC design for cognitive radio networks.
In “Cognitive Medium Access: Constraining Interference Based on Experimental Models,” Geirhofer, Tong, and Sadler consider a cognitive radio coexisting with multiple parallel WLAN channels while abiding by an interference constraint; they propose a Cognitive Medium Access (CMA) recasting the coexistence problem as one of constrained Markov decision processes.
In “HC-MAC: A Hardware-constrained Cognitive MAC for Efficient Spectrum Management,” Jia, Zhang, and Shen study the problem of conducting efficient spectrum management in ad hoc cognitive network while taking the hardware constraints into consideration; they propose a hardware-constrained cognitive MAC to perform efficient spectrum sensing and spectrum access decision.
In “Cross-Layer Based Opportunistic MAC Protocols for QoS Provisionings Over Cognitive Radio Wireless Networks,” Su and Zhang integrate the spectrum sensing at physical layer with the packets scheduling at MAC layer, for the wireless ad hoc networks.
The fourth set of four papers addresses the spectrum sharing and cognitive networking.
In “Distributed Rule-Regulated Spectrum Sharing,” Cao and Zheng consider the problem of efficient and fair spectrum access in dynamic spectrum Networks; they propose a distributed spectrum management scheme using implicit coordination instead of requiring a common communication channel.
In “Spectrum Sharing for Multi-hop Networking with Cognitive Radios,” Hou, Shi, and Sherali investigate the problem of multi-hop networking with cognitive radio nodes, each node has a pool of frequency bands that can be used for communication; they develop a mathematical formulation with the objective of minimizing the required network-wide radio spectrum resource for a set of user sessions.
In “Cognitive Wireless Mesh Networks with Dynamic Spectrum Access,” Chowdhury and Akyildiz propose a COgnitive Mesh NETwork (COMNET) algorithmic framework which realizes an intelligent frequency-shifting selfmanaged mesh network.
The last set of three papers is related to the applications of game theory in cognitive radio networks.
In “Multi-Stage Pricing Game for Collusion-Resistant Dynamic Spectrum Allocation,” Ji and Liu use multi-stage dynamic games to model the spectrum allocation in wireless networks with multiple selfish legacy spectrum holders and unlicensed users; they propose a pricing-based collusionresistant approach to optimize overall spectrum efficiency, while not only keeping the participating incentives of the selfish users but also combating possible user collusion.
In “Competitive Pricing for Spectrum Sharing in Cognitive Radio Networks: Dynamic Game, Inefficiency of Nash Equilibrium, and Collusion,” Niyato and Hossain study the problem of spectrum pricing in a cognitive radio network where multiple primary service providers compete with each other to offer spectrum access opportunities to the secondary users; they use Bertrand game model to analyze the impacts of several system parameters such as spectrum substitutability and channel quality on the Nash equilibrium.
In “Spectrum Leasing to Cooperating Secondary ad hoc Networks’, Simeone, Stanojev, Savazzi, Bar-Ness, Spagnolini,and R. Pickholtz consider the scenario that a primary link has the possibility to lease the owned spectrum to an ad hoc network of secondary nodes in exchange for cooperation in the form of distributed space-time coding; they formulate the investigated model in the framework of Stackelberg games.
In closing, we would like to thank all of the authors who have submitted papers to this Special Issue and the reviewers who helped evaluate the submissions. We would also like to express our gratitude to Laurel Greenidge, Pamela Cosman, Marlene Sealey-Frey and Sue Lange, who have provided significant help and support throughout the whole process. Finally, we hope the contents of this Special Issue will inspire the readers to investigate many of the challenging problems in this emerging field.
PS: Above this paper, now the CR's research is include spectrum sensing, physical layer, MAC design, spectrum sharing and cognitive networking and applications of game theory. I should study deeply and find some interested aspects of CR. Then I can do some reaserch by meself.
