Resource Allocation For Transmission Research Articles

A GLRT approach to data-aided timing acquisition in UWB radios-Part II: training sequence design

The overall system efficiency of impulse radio communications relies critically on judicious allocation of transmission resources, a portion of which should be used to ensure successful timing acquisition. In data-aided mode, optimum timing offset estimation depends not only on the mechanism used for energy capture and the acquisition algorithm employed to recover timing information, but also on the training sequence (TS) pattern from which the timing information is to be extracted. Furthermore, the transmission resources used for timing have to be balanced with that for conveying information messages in order to strike desirable tradeoffs between timing accuracy and information rate. In Part I of this paper, data-aided timing offset estimation is derived based on the maximum likelihood (ML) criterion, where only symbol-rate samples are needed for low-complexity receiver processing. To minimize the mean-square timing errors of these ML synchronizers while at the same time maximizing the average system capacity, TS design and transmit power allocation are investigated in this paper. The optimum training pattern and the number, placement, and power distribution between training and information-bearing symbols are formulated as a resource allocation optimization problem whose solution optimizes system-level performance with the minimum amount of resources consumed.

Channel-Adaptive Resource Allocation for Scalable Video Transmission Over 3G Wireless Network

The paper addresses the important issues of resource allocation for scalable video transmission over third generation (3G) wireless networks. By taking the time-varying wireless channel/network condition and scalable video codec characteristic into account, we allocate resources between source and channel coders based on the minimum-distortion or minimum-power consumption criterion. Specifically, we first present how to estimate the time-varying wireless channel/network condition through measurements of throughput and error rate in a 3G wireless network. Then, we propose a new distortion-minimized bit allocation scheme with hybrid unequal error protection (UEP) and delay-constrained automatic repeat request (ARQ), which dynamically adapts to the estimated time-varying network conditions. Furthermore, a novel power-minimized bit allocation scheme with channel-adaptive hybrid UEP and delay-constrained ARQ is proposed for mobile devices. In our proposed distortion/power-minimized bit-allocation scheme, bits are optimally distributed among source coding, forward error correction, and ARQ according to the varying channel/network condition. Simulation and analysis are performed using a progressive fine granularity scalability video codec. The simulation results show that our proposed schemes can significantly improve the reconstructed video quality under the same network conditions.

Downlink radio resource allocation for multibeam satellite communications

To increase system capacity and allow downlink beams to share orthogonal radio resources, a synchronous transmission for downlink signals in a multibeam satellite communication system is proposed. Also presented is an optimum radio resource allocation for packet transmission in the synchronous multibeam system.

Decision Tools for Electricity Transmission Service and Pricing

This paper considers two methods for transmission service to the electric grid users in a market structure with both long-term bilateral agreements and short-term spot market. The first type of service is the one in which a transmission system provider is the main decision maker solving optimization at the system-wide level. The second type of service allows for the system users to indirectly control flows on the grid by deciding how much demand to exert for system use. Both formulations fall under the category of optimal transmission resource allocation problems. The formulations in this paper require solutions to a stochastic dynamic programming problem. The paper emphasizes process characterization and the assessment of the computational tools for solving the underlying stochastic optimization problems.

Roles and characteristics of television and some implications for distance learning

The Open University has a unique partnership with the BBC. The BBC produces television, radio and audio‐cassette material in conjunction with Open University academic and other course design staff. Producers are full members of course teams. The Government, through its grant to the University, pays the full cost of the BBC's services to the University. The BBC has set up a department (BBC/OUP) specifically to provide services to the Open University. In Autumn, 1981, a brand‐new, £5½ million purpose‐built studio complex became operational on the University campus, and is managed by the BBC on the University's behalf. Currently, over 1,500 Open University television programmes are transmitted each year on the BBC's national television networks. The University funds a small research group to investigate the use of audio‐visual media in the University. The research group carries out studies of programme utilisation across the 140 different courses, to assist with the planning and allocation of production and transmission resources. It also carries out more detailed research into individual programmes and course strategies for using television. More recently, the research group has been paying particular actention to how students learn from television. This paper explores some recent theory, and research developments on the role and character of television, and its impact on learning in distance education.

Message link protocol (MLP)

This document is a specification of the Message Link Protocol (MLP). The MLP creates a transport service between session control entities via transport connections, and some additional session control service. It is based on virtual circuits a la X.25. It is concerned with transport connection establishment and termination, and handles resets and clears to provide a reliable transport service. Furthermore it provides synchronization support related to session establishment, termination and negotiation. The allocation of transmission resources to connections is also considered. It is assumed that the flow control capabilities of the X.25 virtual circuits can be used for transport connection flow control. If, for other transmission media, flow control may not be assumed, an additional function to provide flow control at the transport service level has to be introduced.

Large scale control problems in electric power systems

The main large-scale control problems in electric power system operation, from optimal allocation of generation and transmission resources to network state estimation, frequency and exchange power control, system stability and dynamic security, are illustrated and the methods presently used to solve them are recalled. Special attention is given to significant applications of decomposition by physical decoupling and relaxation or by time-division of decentralized controls, of coordination and hierarchies, with a brief mention of large system analysis areas open to further development.