Search for: davoodi--a
Article IET Communications ; Volume 7, Issue 13 , September , 2013 , Pages 1338-1347 ; 17518628 (ISSN) ; Golami Davoodi, A ; Aref, M. R ; Sharif University of Technology
For a fading full-duplex decode-and-forward relay channel, the authors analytically derive optimum power allocation schemes subject to individual power constraints at the source and the relay. The authors prove that the problem is a convex optimisation problem over the feasible power set, and by proposing a systematic technique to solve min-max problems, optimum power allocations are derived in closed-forms. Finally, for a Rayleigh-fading channel model, optimum power allocations are derived and the respective achievable rate and an upper bound are evaluated. The implications of the derived theoretical results are discussed through some graphs
Article 2012 IEEE Information Theory Workshop, ITW 2012 ; 2012 , Pages 412-416 ; 9781467302234 (ISBN) ; Emadi, M. J ; Davoodi, A. G ; Aref, M. R ; Sharif University of Technology
In this paper, lattice based coding is used over two-user Gaussian state-dependent multiple access channel with common message for two channel models. First, it is assumed that the additive channel interference is noncausally known at both encoders. Exploiting a lattice encoding and decoding scheme, the effect of the interference is completely removed and the capacity region is achieved. Then, the multiple access channel with two additive interferences is considered in the case, where each interference is known noncausally to the associated transmitter. A pure lattice based encoding and decoding structure is proposed and an inner bound on the capacity region is derived which is valid for the...
Article 2019 IEEE International Conference on Industrial Technology, ICIT 2019, 13 February 2019 through 15 February 2019 ; Volume 2019-February , 2019 , Pages 1778-1783 ; 9781538663769 (ISBN) ; Yaghoubi, M ; Davoodi, A ; Ouni, S ; Zolghadri, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc 2019
In a transformerless grid-connected photovoltaic system, many issues arise from the leakage current flow into the ground, as EMI problems. The leakage current is originated from the common-mode voltage fluctuations. In this paper, the common-mode voltage harmonics in a three-phase quasi-Z-source inverter are analyzed using Fourier transform and a closed-loop formulation is presented for the harmonics value. The shoot-through mode in a quasi-Z-source inverter causes extra fluctuations in the common-mode voltage comparing to a classic inverter. The proposed harmonic analysis method provides a systematic way to figure out how shoot-through mode and also other parameters affect the common-mode...
Article IEEE Sensors Journal ; Volume 20, Issue 1 , 2020 , Pages 135-142 ; Davoodi, A ; Saneie, H ; Tootoonchian, F ; Nasiri-Gheidari, Z ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc 2020
Resolvers as position sensors need a high frequency AC excitation voltage, and the induced voltage in their 2-phase perpendicular windings are amplitude modulated (AM) signals. For calculating the position, it is required to demodulated the output signals and calculate their envelopes. Then, inverse tangent can be used for calculating the position. Despite the advantages of resolvers, there are some drawbacks in their application. Calculating the envelopes is always one of the deep concerns in using resolvers. Furthermore, due to low-amplitude of the excitation flux, the performance of the resolvers is strongly affected by electromagnetic interference by the stray fields of motor and brake....