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In spectrum aggregation (SA), two or more component carriers (CCs) of different bandwidths in different bands can be aggregated to support wider transmission bandwidth. The current resource scheduling schemes for spectrum aggregation are not optimal or suitable for CR based heterogeneous networks (HetNets). Consequently, the authors propose a novel resource scheduling scheme for spectrum aggregation...
There are some challenges associated with the spectrum sensing for cognitive radio (CR), one main challenge of spectrum sensing is hardware requirements. The paper proposes the energy detection and a direct-conversion spectrum sensing receiver (DCSSR) to respond to the challenge of hardware requirements. However, the main problem is DC offsets of the DCSSR. A DC offset adaptive energy detection (DC-AED)...
In cognitive radio system, it is still a problem that resources scheduling is unfairness if secondary users (SUs) locate at the disadvantage position around the base station when spectrum aggregation technology is involved to support high speed data transmission. A positional proportional fairness scheduling is advised based on spectrum aggregation to solve this problem. This paper focuses on the...
The low spectrum utilization has limited the development of wireless communication is a common view In Cognitive Radio (CR). And the idle spectrum holes are too narrow to support high-speed communication is an another problem. The spectrum aggregation technology is supposed a hopeful method for the secondary users (SU) access to the idle spectrum. In order to improve the spectrum utilization, a spectrum...
Cognitive radio is based on the thought of adaptive frequency allocation. It solves the problems of spectrum lack and spectrum inefficiency in current communication networks. In this paper we propose a solution using Artificial Neural Networks (ANNs) to replace a complicated frequency allocation system in the cognitive radio. The solution will make sure that the frequency allocation working well in...
Spectrum aggregation (SA) is known as a technology permitting a primary user (PU) or a secondary user (SU) to occupy several idle bands simultaneously for transmitting numerous data. In LTE-A scenario, users can apply SA technology for media broadcasting or network video by utilizing scatted spectrum fragments. However, it's still a problem that how the number of handoff and the delay of a secondary...
In a cognitive radio network based on underlay, the secondary users need to ensure that the interference to the primary users does not exceed the maximum interference tolerance. In this paper, a new algorithm of power allocation is proposed by solving optimal problem according to the theory of duality. The algorithm proposed can satisfy both the limitation of interference tolerance and the requirement...
The cognitive radio is based on the thought of adaptive channel allocation. It solves the problems of spectrum lack and spectrum inefficiency in current communication networks. In this paper we propose an improved algorithm to the channel allocation in the cognitive radio based on potential game theory aimed at minimizing the system interference. The improved algorithm will accelerate the game to...
Process of spectrum allocation is equivalent of rental market in cognitive radio, in order to rent free spectrum of authorized users to cognitive users. the lessors of Spectrum( between authorized users )use the methods of competition between authorized users, Lessees of Spectrum( between cognitive users ) also used the methods of game, the spectrum allocation between authorized user and cognitive...
To solve the problem of low system yield of existing spectrum allocation algorithm in cognitive radio, an advanced algorithm based on system yield and maximal independent set (MIS) is proposed. The advanced algorithm is based on coloring model of spectrum allocation and the theory of MIS. The key part of this algorithm is to calculate priority of channels using system parameters such as amount of...
In cognitive radio networks (CRNs), different received signal-to-noise ratios (SNRs) of secondary users (SUs) lead to different reliability of their local spectrum sensing decisions, and then greatly affect sensing capability of cooperative spectrum sensing. Cooperative spectrum sensing with traditional hard decisions can not improve sensing capability efficiently due to allocating the same weight...
Cognitive radio network technology brings a novel approach to share the open spectrum flexibly and efficiently. However, how to further improve the network construction for reducing the redundant information has become the hot topic. Minimum independent dominating set (MIDS) in graphs is a classic problem in operations research with important application in network construction design. The single...
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