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Most researches on the massive multiple-input multiple-output (MIMO) systems are based on the assumption that the MIMO channels are independent, in reality, the above assumption is very difficult to realize when the number of multiple antennas are very large. Hence the simulation on massive MIMO systems under correlated channels has some degree of guiding significance for practical application of...
Pilot subcarriers are very useful in the measurement of channel indicator such as CINR, frequency offset estimation and channel estimation. They are applied widely in many existing standards such as IEEE 802.11, IEEE 802.16 and IEEE 802.22. In this paper, a set of pilot patten is proposed for a network operating in VHF/UHF band based on 802.16 WiMax design pattern. Rationales behind the choice of...
This paper introduces a new architecture for OpenFlow deployment across international boundaries which are more cost effective and scalable called Hybrid OpenFlow Networking (HON) architecture. The HON architecture divides the OpenFlow network into three domains: Wide Area domain, Local Area domain and User domain. Wide Area domain forms the OpenFlow network backbone comprising hardware-based OpenFlow...
This paper reviews target localization methods in wireless sensor networks. Target localization methods have been investigated extensively due to their wide applications. Main target localization methods include time delay of arrival methods, direction of arrival methods, energy-based target localization methods, radio mapping methods and so on. In this paper, three main categories of localization...
Interference management in femtocell network is an important issue to achieve the network throughput gain as well as not degrading the throughput of the macrocell tier. In this paper we consider a MIMO femtocell network and propose an interference mitigation strategy using interference alignment (IA) to mitigate the interference at the macrocell users (MUEs) caused by femtocell base stations (FBSs)...
In this paper, we propose an anti-interference cooperative spectrum sharing strategy in cognitive two-phase full-duplex relaying networks, in which the secondary system acts as a decode-and-forward relay to assist the primary system achieve the target transmission rate. As a reward, the secondary system can gain access to the licensed primary spectrum to transmit its own signal in both two phases...
The localization of a wireless device is important for current wireless networks, therefore this paper investigates the time-sum-of-arrival (TSOA) based localization method, where the Taylor Series algorithm is analytically derived according to the elliptical geometry, i.e., TSOA based Taylor Series method, and then the conventional time-difference-of-arrival (TDOA) based algorithm is provided as...
The deployment of wide-area OpenFlow networks is essential for the global research community. Since 2011, we started to operat our wide-area OpenFlow networks as a RISE OpenFlow testbed for researchers and developpers. Through our operation, we got some issues. Especially, we focused on the issue caused by topology between sites. By this issue, we cannot assign user's OpenFlow Switches freely. Also,...
This paper proposes a new degree distribution for systematic fountain codes by analyzing the property of systematic code. The erasure probabilities are also taken into consideration during the design. The simulation shows that the new distribution needs less encoding packets to recover all the source packets, has rapid constringency speed, and its performance is not very sensitive to the erasure probabilities.
We propose an analytical expression to evaluate the distribution of link lifetimes in a mobile ad hoc network (MANET) under the Random Waypoint mobility model. We compare this model with a model found in the literature to derive residual link lifetimes. From the derived model, numerical results are evaluated and compared. We found that the residual link lifetime has link durations that last longer...
This paper presents an analytical method for one to compute the centroid of the overlapping area of two intersecting circles with arbitrary orientation. We also extend the solution to estimate the centroid of the overlapping area of three intersecting circles. Furthermore, based on the analytical solution of centroid computing, we propose a cell-based localization technique, namely Centroid Based...
The IPv6 Routing Protocol for Low-power and Lossy Networks (RPL) allows a node to operate in storing or non-storing mode. However, as the network size increases, non-storing RPL will introduce lots of communication overhead, while storing RPL will consume lots of memory. In this paper, we improve the storing mode in RPL by reducing the memory consumption. Our performance studies show that our scheme...
This paper reviews sensor selection methods for distributed detection, distributed estimation and distributed tracking in wireless sensor networks. Before the discussion of different sensor selection methods, brief introductions of distribution detection, distribution estimation and distributed tracking are presented respectively. Future research directions are also given to facilitate further research...
A joint routing and random network coding approach is introduced for the multi-session networks. With the proposed approach, part of the information is transmitted using routing, to reduce the inter-session interference, and the rest of the information is randomly combined at the intermediate nodes with proper precoding at the source nodes. The path used for routing and the corresponding routing rate...
Despite the development of virtualization technologies in computing resources, how best to build virtual networks is still an open issue. Virtual network is an important technology that can hide physical network topologies and policies and provide a dedicated virtual computing environment for each user. However, it is difficult to figure out the actual mapping between a physical network and a virtual...
While lookup table (LUT) is widely used in virtually every kind of computing devices, to achieve low access latency with low cost is always challenging. Although Content-Addressable Memory (CAM) can be used to implement LUT, it is not very cost-effective to add such an expensive device dedicated for LUT in most cases. On the other hand, using hash functions to implement LUT, which can achieve O(1)...
In this paper, we consider relay selection technique in a cooperative cellular network where user terminals act as relays to help the communications between a base station (BS) and cell-edge users (CEUs). We firstly build cooperative sets for source mobile users according to their transmission radius. Then, transmission power sets are built for all mobile users according to SNR thresholds. Finally,...
With the high-speed development of WEB 2.0, the number of web applications continues to grow, making users' behavior become increasingly complex and difficult to monitor. In this paper, we develop a new method for user's behavior characteristics visualization and special user identification. Firstly, we divide all the web applications into 12 kinds and each kind includes several specific applications...
In wireless ad hoc networks, power control has great impact on routing since transmission range is directly determined by a node's transmission power. Higher power can give higher connectivity and shorter path. However, larger transmission range causes more interference to nearby neighbors and may further impair overall network performance. We propose a Q-Learning-based Power-Controlled Routing (QLPCR)...
Advances in the RFID technology has made it universally present especially in the field of logistics for goods tracking. However, more and more applications are emerging enabling RFIDs to be used in a abundance of unique scenarios. Presence of moisture in an LPG, LNG pipe can decrease the quality of the gas and is one of a major problem for the industry. A wireless monitoring system using low frequency...
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