The reason why cellular mobile telephony systems exist is that they allow frequency reuse. Dynamic allocation algorithms improve the network efficiency and the service quality. Dynamic allocation is closely related to...
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The reason why cellular mobile telephony systems exist is that they allow frequency reuse. Dynamic allocation algorithms improve the network efficiency and the service quality. Dynamic allocation is closely related to the following instantaneous allocation problem: given a number of channels (frequencies), a cell structure and the number of calls to be accommodated in each cell, find the optimum allocation of channels to cells subject to restrictions concerning the distance of cells, where the same frequency can be reused. In this paper we formulate and solve this problem by showing that it can be reduced to a 0-1 programming problem. Finally we present results, and draw subsequent conclusions.
作者：
FUJIWARA, ETANAKA, TMemberFaculty of Engineering
Tokyo Institute of Technology Tokyo Japan 152 Eui Fujiwara:received his B.S. and M.S. degrees in Electronics Engineering in 1968 and 1970
respectively and his Dr. of Eng. degree in 1981 all from Tokyo Institute of Technology. In 1970 he joined the NTT Musashino Electrical Communication Laboratories and engaged in developing PIPS-1 and PIPS-11 computer systems. In 1988 he joined the Department of Computer Science Tokyo Institute of Technology as an Associate Professor. In 1990 he became a full Professor. He was a Visiting Professor at the Center for Advanced Computer Studies the University of Southwestern Louisiana from June 1985 to July 1986. His current research interests include coding theory for computers fault-tolerant memories VLSI defect-toleranceand WSI systems. He is a co-author ofError Control Coding for Computer Systems(Prentice-Hall1989) EssentiaLF of Error-Correcting Coding Techniques (Academic Press 1990) and other books. Dr. Fujiwara received the Young Engineer Award from the I.E.I.C.E. in 1978 and the Teshima Memorial Research Award in 1991. He is a senior member of the IEEE and a member of the Information Processing Society Japan. Associate Member
Because of its capability of high-speed search, the associative memory (CAM) is expected to be used in a variety of information processing systems. In this paper, novel fault-tolerant techniques which are effective fo...
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Because of its capability of high-speed search, the associative memory (CAM) is expected to be used in a variety of information processing systems. In this paper, novel fault-tolerant techniques which are effective for on-line use are proposed for TLB which is an example of the application of CAM. First, fault and error models of the TLB consisting of the CAM part and the SRAM part are clarified. Then, the fault-tolerant techniques for these faults and errors, such as distance separable technique, cod-ing technique, simplified 1-out-of-n check and graceful degradation, are proposed. The distance separable technique which encodes the data stored in the CAM part is the one which masks the faulty CAM part and prevents errors from propagating to the subsequent circuits. The coding technique checks the one-to-one correspondence between the data in the CAM and those in SRAM by using the SEC-DED code with byte error detection capability, i.e., SEC-DED-SbED code, and at the same time it detects and corrects errors in the data stored in SRAM. The simplified 1-out-of-n check processes association errors. The graceful degradation gives a flag in the faulty memory section and prevents it from being used. The methods proposed in this paper are evaluated from area augmentation and error detection capability perspectives. The results show that the fault-tolerant TLB with 32 virtual address bits, 32 physical address bits and 128 entries gives single fault detection probability of nearly 99 percent with 28 percent area increase.
Reports MOSFETs with noise figures as low as 0.9 dB at 2 GHz, the lowest achieved to date with Si FETs. The devices were fabricated in thin-film silicon-on-sapphire, with gate lengths (defined by optical lithography) ...
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Reports MOSFETs with noise figures as low as 0.9 dB at 2 GHz, the lowest achieved to date with Si FETs. The devices were fabricated in thin-film silicon-on-sapphire, with gate lengths (defined by optical lithography) drawn at 0.5 /spl mu/m. The devices employed T-gate structures, with extra added aluminum to minimize gate resistance. The microwave gain was high: f/sub max/ values were as high as 52 GHz (near record performance) for nMOS and 32 GHz far pMOS transistors; f/sub t/ values were 17 GHz and 13 GHz for nMOS and pMOS respectively.
Modal transformation technique is a common tool for transmission line transient computations. A simplified modal decomposition of overhead transmission lines, suitable for time‐domain switching (up to 105 Hz) transie...
In this paper we present a design scheme for output tracking of nonlinear systems that are subject to regular perturbations. We show that applications of singular perturbation theory to the input-output feedback linea...
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In this paper we present a design scheme for output tracking of nonlinear systems that are subject to regular perturbations. We show that applications of singular perturbation theory to the input-output feedback linearization technique provides a systematic method to identify the slow "dominant" states and fast "negligible" states. Similar to the backstepping design technique, a suitable state variable is converted into a "control like" variable which in the steady state is forced to approach the desired tracking control law for the reduced order system. We show that this design achieves stable approximate tracking of reasonable reference trajectories for nonlinear systems that are "dominantly" minimum phase. The order of approximation can be arbitrarily improved by addition of correction terms in the control law. The main advantage of this approach is that the design is often performed for a much simpler model which is linear in the new control variable and describes the dominant part of the original system by ignoring some of the fast states that are forced to have little effect on the steady state performance.< >
We review some of the existing results on the Lyapunov design of robustly stabilizing feedback laws for uncertain nonlinear systems. Using the concept of a robust control Lyapunov function, we present robust backstepp...
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We review some of the existing results on the Lyapunov design of robustly stabilizing feedback laws for uncertain nonlinear systems. Using the concept of a robust control Lyapunov function, we present robust backstepping tools and demonstrate how they can be used in systematic design procedures.< >
We extend the concept of a robust control Lyapunov function (RCLF) for nonlinear systems to the case of measurement feedback. We explore conditions under which the existence of an RCLF is sufficient and/or necessary f...
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We extend the concept of a robust control Lyapunov function (RCLF) for nonlinear systems to the case of measurement feedback. We explore conditions under which the existence of an RCLF is sufficient and/or necessary for robust global stabilizability via continuous static or dynamic measurement feedback.< >
A two-stage multiuser detector for the code division multiple access environment employing a combination of a decorrelator and a nonlinear multiuser interference canceler is considered. The weights of the canceler are...
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This paper studies the ability of the exponentially weighted RLS algorithm to track a doppler shifted BPSK communications signal. This is modeled as a chirped AR1 process in Gaussian white noise. Expressions for the o...
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This paper deals with necessary conditions for integral and exponential-of-integral cost functions, when the signal is a controlled diffusion process, and the observations consist of continuous and discontinuous proce...
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This paper deals with necessary conditions for integral and exponential-of-integral cost functions, when the signal is a controlled diffusion process, and the observations consist of continuous and discontinuous processes. These problems are reformulated as infinite dimensional stochastic problems having full information, with state of the Zakai equation for the integral cost, and the information state for the exponential-of-integral cost. The approach is the one considered by Bensoussan (1992) for the case of integral cost with continuous observations.< >
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