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Ye J.,Key Laboratory of Cognitive Radio and Information Processing | Ye J.,Guangxi Key Laboratory of Information and Communication | Wang J.-X.,Central South University | Huang J.-W.,Central South University
International Journal of Communication Systems | Year: 2011

The fair allocation of resources among different nodes is one of the critical problems in wireless mesh networks. Existing solutions mainly focus on rate-limitation policies or distributed fair MAC schemes at the potential expense of total network utilization. This paper investigates a special starvation problem among TCP flows that are different hops away from the BS, as well as its recently proposed solution, the 'Minimum Content Window' policy based on IEEE 802.11e. It is found that the aggregate throughput degrades sharply because the effect of this policy on the TCP congestion mechanism has been overlooked. This paper proposes a priority-based congestion control by using 'Cross-Layer Explicit Congestion Notification'. Analysis and simulation results demonstrate that our scheme can improve the fairness of TCP flows while the aggregate throughput is at least 20% higher than the 'Minimum Content Window' policy. © 2011 John Wiley & Sons, Ltd. Source


Deng R.,Zhejiang University | Yang Z.,Zhejiang University | Yang Z.,Key Laboratory of Cognitive Radio and Information Processing
IEEE International Conference on Control and Automation, ICCA | Year: 2014

Smart grid has been widely considered to be the next generation of power grid, which incorporates smart meters and two-way communications to improve the agility, reliability, efficiency, security, economy and environmental friendliness. One of the key foundations of smart grid is real-time access to meter data via a reliable communication infrastructure. In this paper, we introduce promising wireless communication technologies to fundamentally improve the meter data transmission within smart grid. Furthermore, we propose a cooperative transmission game which aims to improve the reliability of smart grid communication. Numerical results evaluate the effectiveness of the proposed approach. © 2014 IEEE. Source


Fan L.,Shantou University | Fan L.,Xidian University | Fan L.,Key Laboratory of Cognitive Radio and Information Processing | Lei X.,Southwest Jiaotong University | And 2 more authors.
European Transactions on Telecommunications | Year: 2014

This letter considers a multiuser two-way relay network with a single fixed-gain amplify-and-forward relay, where there are M antennas at the base station (BS) and N mobile stations. Depending on the channel conditions, one best antenna from BS and one best user are selected to communicate with each other. We study the impact of channel estimation error to the system over Rayleigh fading environments. In particular, a closed-form expression is obtained for system outage probability. It is found that an error floor appears in the outage probability as long as the channel estimation is imperfect. We further study the power allocation (PA) among the network nodes to minimise the outage probability. Numerical results are presented to evaluate the effects of both channel estimation error and PA on the system performance. © 2012 John Wiley & Sons, Ltd. Source


Yang C.,Key Laboratory of Cognitive Radio and Information Processing | Zheng L.,Key Laboratory of Cognitive Radio and Information Processing | Zheng L.,Science and Technology on Information Transmission and Dissemination in Communication Networks Laboratory | Bai Y.,Key Laboratory of Cognitive Radio and Information Processing
WSEAS Transactions on Communications | Year: 2014

To ensure the reliability of transmission and prevent inter-carrier interference (ICI) between subbands, the sub-carrier frequency increment is usually greater than the bandwidth of sub-band for multi-carrier chirp. That will bring on false targets generated by pseudo peaks on High Resolution Range Profile (HRRP). At the presence of false targets, it is difficult to get the true position of target due to the serious influence on target detection. In this paper, the mechanism of pseudo peaks generation is analyzed and an algorithm is proposed to remove pseudo peaks while the image resolution is improved by Super-SVA, which reduces the echo pulse width. With the pulse width less than an unambiguous range, the HRRP without false targets can be obtained. With the analysis and simulation of single and multi-targets, the results indicate that this algorithm can effectively remove false targets caused by the pseudo peaks. Source


Huang S.,Key Laboratory of Cognitive Radio and Information Processing | Chen H.,Key Laboratory of Cognitive Radio and Information Processing | Chen H.,Nanjing Southeast University | Zhao F.,Key Laboratory of Cognitive Radio and Information Processing
7th International Conference on Wireless Communications, Networking and Mobile Computing, WiCOM 2011 | Year: 2011

Many cooperative spectrum sensing schemes in cognitive radio networks have been proposed. However, aggregation node selection was rarely considered which can improve the performance of cooperative spectrum sensing. We consider a cognitive radio network consisting of a primary user and multiple cognitive users. One of the cognitive users will be selected as the aggregation node which directly receives the primary signal and indirectly collects the primary signal relayed by the other cognitive users. The signal-to-noise ratios of the received primary signal at different cognitive users usually are not identical because the channel gain from one cognitive user to another cognitive user is different. Thus, an aggregation node selection scheme is proposed in order to achieve better detection performance. The detection probability and false alarm probability are derived and simulated. The results show that for better detection performance, the cognitive user with higher received signal-to-noise-ratio should be selected as the aggregation node. © 2011 IEEE. Source

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