Browsing by Author "Su, Yu Ted"

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Energy-Efficient Scheduling for Wireless Communication System
(2012)
Lin, Kuhn-Chang
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Lai, Jiun-You
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Su, Yu Ted
;
交大名義發表
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National Chiao Tung University
Energy-efficient scheduling problem in wireless communication system is investigated in this paper. We propose two near-optimal schedulers which have simple structures for the general hard delay constraint scenario. Both single-user and multiuser cases are considered. The first scheduler invokes Gaussian approximation while the second one is inspired by the inverse water-filling (IWF) approach. The scheduling policies consist of a channel-awareness term and a delay-awareness term. Numerical results show that the proposed policies achieve near optimal performance when the total required transmit bits, R, is large. For the multiuser scenario, our scheduling strategy consists of an initial resource (number of time slots) allocation and a slot-by-slot user selection and bit loading algorithm. The former depends on the rate requirement and a priori knowledge of user-dependent channel statistic while the latter use an order statistic based approach designed to minimize the expected total energy consumption.
New Signal Designs for Enhanced Spatial Modulation
(2016-11)
Cheng, Chien-Chun
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Sari, Hikmet
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Sezginer, Serdar
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Su, Yu Ted
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電子工程學系及電子研究所
In this paper, we present three new signal designs for enhanced spatial modulation (ESM), which was recently introduced by the present authors. The basic idea of ESM is to convey information bits not only by the index(es) of the active transmit antenna(s) as in conventional SM, but also by the types of the signal constellations used. The original ESM schemes were designed with reference to single-stream SM and involved one or more secondary modulations in addition to the primary modulation. Compared with single-stream SM, they provided either higher throughput or improved signal-to-noise ratio (SNR). In this paper, we focus on multi-stream SM (MSM) and present three new ESM designs leading to increasing SNR gains when they are operated at the same spectral efficiency. The secondary signal constellations used in the first two designs are derived through a single geometric interpolation step in the signal constellation plane, while the third design also makes use of additional constellations derived through a second interpolation step. The new ESM signal designs are described for MIMO systems with four transmit antennas out of which two are active, but we also briefly present extensions to higher numbers of antennas. Theoretical analysis and simulation results indicate that the proposed designs provide a significant SNR gain over MSM.
Sequence generating method
(2008-10-23)
Chen, Ching Wei
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Zheng, Yan Xiu
;
Su, Yu Ted
;
Li, Chi Fang
This invention provides a sequence generating method, in which the method has steps of generating R sets of orthogonal sequence with each set of the orthogonal sequence including N elements, generating a low-autocorrelation sequence having N elements, and multiplying the N elements of the low-autocorrelation sequence by the N elements of each of R sets of the orthogonal sequence point-to-point. Therefore, a sequence generated by the method of the present invention has low-autocorrelation and low-crosscorrelation in transmission characteristics of a communication system.
Turbo Equalization of Nonlinear TDMA Satellite Signals
(2009-03-01)
Chen, Yen-Chih
;
Su, Yu Ted
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電信工程研究所
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Institute of Communications Engineering
In this paper, we investigate a coded solution to compensate for the nonlinear distortion of TDMA satellite waveforms. Based on a Volterra-type channel model and the turbo principle, we present a turbo-like that includes a simple rate-I encoder at the transmit side in addition to a conventional channel encoder; the receive side iteratively equalizes the nonlinear channel effect and decodes the received symbols. Some other design alternatives are also explored and computer simulated performance is presented. Numerical results show that significant improvement over conventional approaches can be achieved by the proposed turbo system.