The Experts below are selected from a list of 281127 Experts worldwide ranked by ideXlab platform
Ryuji Kohno - One of the best experts on this subject based on the ideXlab platform.
-
A wireless multimedia CDMA system based on Transmission Power control
IEEE Journal on Selected Areas in Communications, 1996Co-Authors: Ryuji KohnoAbstract:This paper proposes a wireless multimedia code division multiple access (CDMA) system based on Transmission Power control. When we transmit multimedia information (i.e., speech, image, and data), differences in information rate, traffic performance, and required quality should be taken into account. The wireless CDMA system can achieve a flexible balance if Transmission Power distribution is controlled by using channel measurement information, i.e., traffic. In this paper, the optimal control of Transmission Power is derived by linear programming and nonlinear programming. Numerical results using a LAN demonstrate that the proposed method can satisfy the required quality.
-
PIMRC - Wireless multimedia CDMA system based on Transmission Power control
Proceedings of 6th International Symposium on Personal Indoor and Mobile Radio Communications, 1Co-Authors: Ryuji KohnoAbstract:This paper proposes a wireless multimedia CDMA system based on Transmission Power control. When we transmit multimedia information such as speech, image and data, differences in the information rate, traffic performance and required quality should be taken into account. The wireless CDMA system can achieve a flexible balance of these differences if the Transmission Power distribution is controlled using channel measurement information such as traffic. The optimal control of Transmission Power is derived by linear programming and nonlinear programming. Numerical results demonstrate that the proposed method can satisfy the required quality.
Xiue Gao - One of the best experts on this subject based on the ideXlab platform.
-
Transmission Power scheduling and control co-design for wireless sensor networks
Information Sciences, 2018Co-Authors: Shixi Wen, Ge Guo, Bo Chen, Xiue GaoAbstract:Abstract This paper discusses Transmission Power scheduling and control co-design in wireless sensor networks (WSNs) under communication energy constraints, in which the dynamics of all mobile sensor nodes (MSNs) are assumed to be nonlinear. A most regular code sequence (MRCS) is introduced as the Transmission Power scheduling policy to automatically allocate the Transmission Power levels to MSNs thereby adhering to the given communication energy budget. The effects of the different Transmission Power levels on data Transmission is explicitly characterized in this paper. By using a stochastic system analysis approach and average dwell time technique, a framework for the Transmission Power scheduling and control co-design is established. The control co-design algorithm is proposed to simultaneously determine the gain of the sampled-data feedback controller and the parameters of the generated MRCS. A numerical simulation is conducted to verify the effectiveness of the proposed algorithm.
Chungyong Lee - One of the best experts on this subject based on the ideXlab platform.
-
Tomlinson-harashima precoder with tilted constellation for reducing Transmission Power
IEEE Transactions on Wireless Communications, 2009Co-Authors: Jiwon Kang, Dong-seung Kwon, Chungyong LeeAbstract:Tomlinson-Harashima precoder (THP) is being noted for an efficient alternative to dirty paper coder. THP increases the Transmission Power due to the use of the modulo operator. In this paper, we propose a method that reduces the Transmission Power by tilting the constellations of the transmit data symbols. The symbol error rate (SER) is improved for a fixed SNR by reducing the Transmission Power. Average Transmission Power is calculated asymptotically by using an extreme value distribution. We have shown that the Transmission Power can be significantly reduced when we use the tilted constellation THP. As the Transmission Power determines the SER slope, at high SNRs we achieve lower SER than in the case of a Transmission over an AWGN channel. The tilted angle can be estimated at the receiver. An angle estimation algorithm is proposed that optimizes angle estimation error and SER.We use the approximation of the angle estimation error and SER to find an optimum number of tilted angles. By using the proposed angle estimation algorithm and the optimum number of tilted angles, the tilted constellation THP always outperforms the conventional THP algorithm.
-
GLOBECOM - An Improved Tomlinson-Harashima Precoder Reducing Transmission Power
IEEE GLOBECOM 2008 - 2008 IEEE Global Telecommunications Conference, 2008Co-Authors: Jiwon Kang, Dong-seung Kwon, Chungyong LeeAbstract:Tomlinson-Harashima precoder (THP) is an efficient interference pre-canceler, however, the Transmission Power is increased over the symbol Power due to the modulo operation. In this paper, we propose an improved THP that reduces the Transmission Power of the conventional THP by tilting a group of symbols by an angle toward minimizing the Transmission Power. The tilted angle can be either estimated by the receiver or notified by the transmitter using a feed-forward information. Assuming a large interference, the average Transmission Power of the proposed THP is derived by the central limit theorem and Gumbel extreme value distribution. The symbol error rate (SER) and its asymptotic behavior is also derived and compared. The more tilted angles or the smaller size of groups are used, the more Power the proposed THP saves. The Transmission Power can even be less than the symbol Power. Accordingly, in an environment that the Power gain overwhelms the other losses, the SER can be less than the SER of AWGN channel.
Chatschik Bisdikian - One of the best experts on this subject based on the ideXlab platform.
-
conserving Transmission Power in wireless ad hoc networks
International Conference on Network Protocols, 2001Co-Authors: Javier Gomez, Andrew T Campbell, Mahmoud Naghshineh, Chatschik BisdikianAbstract:This paper introduces PARO, a Power-aware routing optimization that helps to minimize the Transmission Power needed to forward packets between wireless devices in ad hoc networks. Using PARO, one or more intermediate nodes called "redirectors" elects to forward packets on behalf of source-destination pairs thus reducing the aggregate Transmission Power consumed by wireless devices. PARO is applicable to a number of networking environments including sensor networks, home networks and mobile ad hoc networks. In this paper, we present the detailed design of PARO and evaluate the protocol using simulation and experimentation. We show through simulation that PARO is capable of outperforming traditional broadcast-based routing protocols (e.g., MANET routing protocols) due to its Power conserving point-to-point on-demand design. We discuss some initial experiences from an early implementation of the protocol in an experimental wireless testbed using off-the-shelf radio technology.
M. Agnes Saranya - One of the best experts on this subject based on the ideXlab platform.
-
Distance based Transmission Power control scheme for indoor wireless sensor network
Transactions on Computational Science XI, 2010Co-Authors: P. T. V. Bhuvaneswari, V. Vaidehi, M. Agnes SaranyaAbstract:This paper proposes a Distance Based Transmission Power Control (DBTPC) scheme for selecting Optimal Transmission Power for Indoor Wireless Sensor Network. The proposed work consists of two phases namely Localization phase and data transfer phase. In Localization phase, the relative coordinate of the unknown sensor node with respect to anchor sensor node is estimated by the proposed Received Signal Strength (RSS) based localization algorithm. By performing neighbor discovery process, each node obtains the distance information of its neighboring nodes. Based on this information, in data transfer phase it dynamically controls its Transmission Power level to reach their neighboring node with acceptable RSS value. This is achieved by the proposed distributed Distance Based Transmission Power Control (DBTPC) scheme. The Optimal Transmission Power (OTP) can be adaptively selected by the proposed DBTPC scheme. This ensures energy efficiency in sensor node and thereby increases the lifetime of the network.
-
ICARCV - Optimal Transmission Power selection under energy constraints for sensor network localization
2010 11th International Conference on Control Automation Robotics & Vision, 2010Co-Authors: P. T. V. Bhuvaneswari, V. Vaidehi, M. Agnes SaranyaAbstract:In a wireless sensor network nodes can be deployed randomly to collect data from an area of interest. So it is mandatory for each node in the network to be aware of its location in the physical world, in order to map the collected information to the base station. Thus, localization becomes an important technique in sensor networks. Further, Power conservation is also an important factor as the nodes are operated with limited battery supply. Hence to increase the lifetime of the network, an energy-efficient localization is required. In this paper, a fine-grained paradigm of localizing sensor nodes based on Received Signal Strength (RSS) under controlled Power of anchor nodes is proposed. The Transmission Power control is achieved by Distance Controlled Transmission Power (DCTP) adjustment algorithm where an anchor node closer to an unknown node operates at low Transmission Power while the one at farther distance operate at high Transmission Power. Thus based on the distance of the unknown node with anchor node, the Transmission Power level of anchor is adjusted. This paper also provides analysis of the impact of various Transmission Power levels on the proposed localization algorithm. Simulation analysis is carried out in Matlab and the results show the performance of the algorithm in terms of localization accuracy and Power consumption.
