Joint Rate Control and Spectrum Allocation under Packet Collision Constraint in Cognitive Radio Networks (original) (raw)
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Utility Maximization with Packet Collision Constraint in Cognitive Radio Networks
IEICE Transactions on Communications, 2012
We study joint rate control and resource allocation with a packet collision constraint that maximizes the total utility of secondary users in cognitive radio networks. We formulate and decouple the original optimization problem into separable subproblems and then develop an algorithm that converges to optimal rate control and resource allocation. The proposed algorithm can operate on different timescales to reduce the amortized time complexity.
QoS constrained resource allocation to secondary users in cognitive radio networks
Computer Communications, 2009
In this paper, we consider a multi-channel cognitive radio network (CRN) where multiple secondary users share a single channel and multiple channels are simultaneously used by a single secondary user (SU) to satisfy their rate requirements. In such an environment, we attempt to evaluate the optimal power and rate distribution choices that each secondary user has to make in order to maintain their quality of service (QoS). Our measures for QoS include signal to interference plus noise ratio (SINR)/bit error rate (BER) and minimum rate requirement. We propose two centralized optimization frameworks in order to solve for the optimal resource management strategies. In the first framework, we determine the minimum transmit power that SUs should employ in order to maintain a certain SINR and use that result to calculate the optimal rate allocation strategy across channels. In the second framework, both transmit power and rate per channel are simultaneously optimized with the help of a bi-objective problem formulation. Unlike prior efforts, we transform the BER constraint into a convex constraint in order to guarantee optimality of the resulting solutions. Simulation results demonstrate that in both frameworks, optimal transmit power follows ''reverse water filling" process and rate allocation follows SINR. We also observe that, due to the ability to adapt both power and rate simultaneously to attain a certain BER, the joint optimization framework results in a lower total transmit power than the two-stage approach.
Resource Allocation Strategies in Cognitive Radio Networks Under QoS Constraints
Evolution of Cognitive Networks and Self-Adaptive Communication Systems
The rapid growth of spectral resources' demands, as well as the increasing Quality of Service (QoS) requirements of wireless users have led to the necessity for new resource allocation schemes which will take into account the differentiated QoS needs of each wireless user. Towards this direction, the researchers have introduced the concept of effective capacity, which is defined as the maximum rate that the channel can support in order to guarantee a specified QoS requirement. This concept has been considered as a "bridge" among the physical layer characteristics and the upper-layer metrics of QoS. During the last years, it has been widely employed for resource allocation problems in various wireless networks leading to efficient mechanisms. This chapter focuses on the employment of the effective capacity theory in Cognitive Radio (CR) systems, presenting an extensive survey on QoS-driven resource allocation schemes proposed in the literature. Some useful conclusions are presented and future research directions on this subject are highlighted and discussed.
Spectrum sharing optimization with QoS guarantee in cognitive radio networks
Computers & Electrical Engineering, 2013
In this paper, we propose an optimized spectrum sharing scheme based on the Hungarian Algorithm to guarantee the quality of service (QoS) for individual cognitive radio (CR) users belonging to different CR cells. The proposed scheme is most favorable for overlapping cells where the users are demanding channels for heterogeneous applications such as chatting, web browsing, or voice and video streaming. The spectrum sharing optimization with the QoS guarantee (SSO-QG) is an optimal scheme that can operate in throughput enhancement mode, high reliability mode and collision avoidance mode based on the weight assigned to the corresponding QoS parameters in accordance with the demands of different applications. Simulation results show that the proposed scheme outperforms the existing schemes in terms of forming the optimal sharing pattern and meeting the stringent QoS requirements fairly enough according to the demands of the cell. Moreover, it reduces collisions with primary users.
QoS-Aware Spectrum Sharing in Cognitive Wireless Networks
IEEE GLOBECOM 2007-2007 IEEE Global Telecommunications Conference, 2007
We consider QoS-aware spectrum sharing in cognitive wireless networks where secondary users are allowed to access the spectrum owned by a primary network provider. The interference from secondary users to primary users is constrained to be below the tolerable limit. Also, signal to interference plus noise ratio (SINR) of each secondary user is maintained higher than a desired level for QoS insurance. When network load is high, admission control needs to be performed to satisfy both QoS and interference constraints. We propose an admission control algorithm which is performed jointly with power control such that QoS requirements of all admitted secondary users are satisfied while keeping the interference to primary users below the tolerable limit. When all secondary users can be supported at minimum rates, we allow them to increase their transmission rates and share the spectrum in a fair manner. We formulate the joint power/rate allocation with max-min fairness criterion as an optimization problem. We show how to transform it into a convex optimization problem so that its globally optimal solution can be obtained. Numerical results show that the proposed admission control algorithm achieves performance very close to the optimal solution. Also, impacts of different system and QoS parameters on the network performance are investigated for both admission control and rate/power allocation problems.
Transactions on Emerging Telecommunications Technologies, 2019
Algorithms for spectrum sharing over resource-limited cognitive radio networks are often designed to solve specific problems. This means that a certain algorithm deals specifically with a certain limited resource, and is not suitable for other resources. This limitation violates the software-defined networking philosophy, where a scheme has to be reprogrammable to cope with different limited resources that can dynamically arise depending on network conditions. In this work, we investigate the problem of spectrum sharing in resource-limited cognitive radio networks. Specifically, we introduce a novel spectrum sharing algorithm that is compatible with software-defined networks, in the sense that it can be reprogrammed to support multiple constraints on resources of different types. A main feature of the proposed scheme is that computations could be distributed across multiple processing units to reduce computational complexity on each unit. In addition, the proposed algorithm is equipped with a fairness scheme. Simulation results demonstrate the efficacy of the proposed scheme.
Optimal Strategy for QoS Provision under Spectrum Mobility in Cognitive Radio Networks
2012 IEEE Vehicular Technology Conference (VTC Fall), 2012
In cognitive radio networks, the arrival of Primary Users (PUs) may force Secondary Users (SUs) to terminate their ongoing sessions or degrade their Quality of Service (QoS) level. Given the time-varying spectrum availability, an immediate challenge arising is to support the QoS of SUs under spectrum mobility. In this paper, we propose an optimal decision-making framework for joint admission control, eviction control and bandwidth adaptation in cognitive radio networks. The problem is formulated as a Semi-Markov Decision Process (SMDP) and the optimal decision for each system state is derived to maximize the long-term network revenue as a function of the spectrum utilization, the SU blocking probability and the bandwidth adaptation cost under the SU dropping probability constraint. It is shown that the derived optimal strategy outperforms the threshold-based channel reservation schemes with/without bandwidth adaptation. And among the schemes with bandwidth adaptation, more performance improvement can be achieved by the proposed one when the bandwidth adaptation cost is taken into account.
Joint rate and power allocation for cognitive radios in dynamic spectrum access environment
IEEE Transactions on Wireless Communications, 2000
We investigate the dynamic spectrum sharing problem among primary and secondary users in a cognitive radio network. We consider the scenario where primary users exhibit on-off behavior and secondary users are able to dynamically measure/estimate sum interference from primary users at their receiving ends. For such a scenario, we solve the problem of fair spectrum sharing among secondary users subject to their QoS constraints (in terms of minimum SINR and transmission rate) and interference constraints for primary users. Since tracking channel gains instantaneously for dynamic spectrum allocation may be very difficult in practice, we consider the case where only mean channel gains averaged over short-term fading are available. Under such scenarios, we derive outage probabilities for secondary users and interference constraint violation probabilities for primary users. Based on the analysis, we develop a complete framework to perform joint admission control and rate/power allocation for secondary users such that both QoS and interference constraints are only violated within desired limits. Throughput performance of primary and secondary networks is investigated via extensive numerical analysis considering different levels of implementation complexity due to channel estimation.
Resource allocation for spectrum underlay in cognitive radio networks
IEEE Transactions on Wireless Communications, 2000
A resource allocation framework is presented for spectrum underlay in cognitive radio networks. We consider both interference constraints for primary users and quality of service (QoS) constraints for secondary users. Specifically, interference from secondary users to primary users is constrained to be below a tolerable limit. Also, signal to interference plus noise ratio (SINR) of each secondary user is maintained higher than a desired level for QoS insurance. We propose admission control algorithms to be used during high network load conditions which are performed jointly with power control so that QoS requirements of all admitted secondary users are satisfied while keeping the interference to primary users below the tolerable limit. If all secondary users can be supported at minimum rates, we allow them to increase their transmission rates and share the spectrum in a fair manner. We formulate the joint power/rate allocation with proportional and max-min fairness criteria as optimization problems. We show how to transform these optimization problems into a convex form so that their globally optimal solutions can be obtained. Numerical results show that the proposed admission control algorithms achieve performance very close to that of the optimal solution. Also, impacts of different system and QoS parameters on the network performance are investigated for the admission control, and rate/power allocation algorithms under different fairness criteria.
Adaptive Resource Optimization For Cognitive Radio Networks
International journal of advanced networking and applications, 2021
In cognitive radio network, the spectrum sensing finds either the channel is occupied or idle, the problem is assigning the unused channels of the primary user (PU) to the secondary users in an efficient manner is most challenging issue. In this work, we investigates the above issue and proposed an adaptive resource allocation to the secondary users in terms of channel allocation and power allocation. The proposed work intelligently handles both frequency and space efficiently without affecting the quality of service (QoS) of the primary user. We considered both underlay and overlay spectrum access, based on that resource allocation is carried out in an efficient manner. The maximum transmitted data rate of the secondary user (SU) obtained is 225Kbps determined by using Shannon channel capacity theorem. The proposed work also shows the effectiveness of the simulation in terms of energy efficiency up to 8.25 x 10 5 bits/Joule.