Search for: power-savings
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    A 32kb 90nm 10T-cell sub-threshold SRAM with improved read and write SNM

    , Article 2013 21st Iranian Conference on Electrical Engineering ; May , 2013 ; 9781467356343 (ISBN) Hassanzadeh, S ; Zamani, M ; Hajsadeghi, K ; Sharif University of Technology
    The constraints of power saving have compelled SRAM designers to consider sub-threshold area as a viable choice. The biggest barrier of this progress is the stability of SRAM's cells and the correct operations. In this paper a 10T cell structure has been proposed with 90% read and 50% write SNM improvement in comparison to the conventional 6T cell. The hold SNM value is about the 6T cell SRAM. Also using differential read method in the proposed structure causes high read performance and using simpler sense amplifier. The symmetric configuration of this structure helps the SRAM has simpler layout and lower transistor mismatch. Using 90nm TSMC CMOS, 32kb 10T cell SRAM in sub-threshold area is... 

    Power consumption evaluation of sleep mode in the IEEE 802.16e MAC with multi service connections

    , Article 2007 IEEE International Conference on Signal Processing and Communications, ICSPC 2007, Dubai, 14 November 2007 through 27 November 2007 ; 2007 , Pages 1363-1366 ; 9781424412365 (ISBN) Pour Nejatian, N. M ; Nayebi, M. M ; Tadaion, A. A ; Sharif University of Technology
    In the sleep mode, a Mobile Subscribe Station (MSS) sleeps for a sleep interval and wakes up at the end of this interval in order to check buffered packet(s) at Base Station (BS) destined to it. If there is no packet, the MSS increases the sleep window up to the maximum value or keeps it unchanged and sleeps again. In this paper, we study the effect of presence of multi service connections with different power saving classes (PSCs) on power consumption for IEEE 802.16e nodes while operating in the sleep mode. Using multi service connections may result in overlapping of availability and unavailability intervals and reducing the effectiveness of power saving mode of the subscriber. © 2007 IEEE... 

    Scheduling to minimize gaps and power consumption

    , Article SPAA'07: 19th Annual Symposium on Parallelism in Algorithms and Architectures, San Diego, CA, 9 June 2007 through 11 June 2007 ; 2007 , Pages 46-54 ; 159593667X (ISBN); 9781595936677 (ISBN) Demaine, E.D ; Ghodsi, M ; Hajiaghayi, M. T ; Sayedi Roshkhar, A. S ; Zadimoghaddam, M ; Sharif University of Technology
    This paper considers scheduling tasks while minimizing the power consumption of one or more processors, each of which can go to sleep at a fixed cost α. There are two natural versions of this problem, both considered extensively in recent work: minimize the total power consumption (including computation time), or minimize the number of "gaps" in execution. For both versions in a multiprocessor system, we develop a polynomial-time algorithm based on sophisticated dynamic programming. In a generalization of the power-saving problem, where each task can execute in any of a specified set of time intervals, we develop a (1 + 23 α)-approximation, and show that dependence on α is necessary.... 

    A reliable and power efficient flow-control method to eliminate crosstalk faults in network-on-chips

    , Article Microprocessors and Microsystems ; Volume 35, Issue 8 , 2011 , Pages 766-778 ; 01419331 (ISSN) Patooghy, A ; Miremadi, S. G ; Tabkhi, H ; Sharif University of Technology
    This paper proposes a power-efficient flow-control method to tackle the problem of crosstalk faults in Network-on-Chips (NoCs). The method, called FRR (Flit Reordering/Rotation), combines three coding mechanisms to entirely eliminate opposite direction transitions (OD transitions) as the source of crosstalk faults in NoC communication channels. The first mechanism, called flit-reordering, reorders flits of every packet to find a flit sequence which produces the lowest number of OD transitions on NoC channels. The second mechanism called flit-rotation, logically rotates the content of every flit of the packet with respect to previously sent flit to achieve even more reduction in the number of... 

    An audio band low voltage CT-ΔΣ modulator with VCO-based quantizer

    , Article 18th IEEE International Conference on Electronics, Circuits, and Systems, ICECS 2011, 11 December 2011 through 14 December 2011 ; December , 2011 , Pages 232-235 ; 9781457718458 (ISBN) Yousefzadeh, B ; Sharifkhani, M ; Sharif University of Technology
    This paper presents the design and implementation of a low power, low voltage, continuous time delta sigma modulator for audio band in 90 nm CMOS technology. A VCO-based integrator and quantizer are used. Inherent dynamic element matching (DEM) of the quantizer eliminates the need for explicit DEM logic which results in a short excess-delay and power saving. Simulation results show that the modulator achieves 78 dB SNDR and 87 dB SNR in a 20 kHz input bandwidth and dissipates 106 μW from 1 V supply. The power consumption for different parts is discussed  

    Energy consumption analysis of the stepwise adiabatic circuits

    , Article Microelectronics Journal ; Volume 104 , October , 2020 Khorami, A ; Saeidi, R ; Sharif University of Technology
    Elsevier Ltd  2020
    In this paper, an analytic model of the energy consumption of the Stepwise Adiabatic Circuits (SAC) when it is possible to discharge the load capacitor is proposed. Using this model, analytical derivations are calculated which shows us the power saving of the SACs. Using analytical derivations, the sizing of a capacitor tank is determined for a desired energy saving. For example, the derivations predict that if the sizing of the 3-step series tank capacitors is equal to the load capacitor, the power saving is 55%. Also, if the sizing of the tank is very large the energy saving of a 3-step stepwise charging is equal to 66.7%. Several Simulations in 0.18μm CMOS technology prove the accuracy of... 

    An adaptive approach to manage the number of virtual channels

    , Article 22nd International Conference on Advanced Information Networking and Applications Workshops/Symposia, AINA 2008, Gino-wan, Okinawa, 25 March 2008 through 28 March 2008 ; 2008 , Pages 353-358 ; 1550445X (ISSN) ; 0769530966 (ISBN); 9780769530963 (ISBN) Mirza Aghatabar, M ; Koohi, S ; Hessabi, S ; Rahmati, D ; Sharif University of Technology
    Network-on-Chip (NoC) is a precious approach to handle huge number of transistors by virtue of technology scaling to lower than 50nm. Virtual channels have been introduced in order to improve the performance according to a timing multiplexing concept in each physical channel. The incremental effect of virtual channels on power consumption has been shown in literatures. The issue of power saving has always been controversial to many designers. In this paper, we introduce a new technique which tries to adaptively mange the number of virtual channels in order to reduce the power consumption while not degrading the performance of the network without any reconfiguration. Our experimental results... 

    Data center power reduction by heuristic variation-aware server placement and chassis consolidation

    , Article CADS 2012 - 16th CSI International Symposium on Computer Architecture and Digital Systems ; 2012 , Pages 150-155 ; 9781467314824 (ISBN) Pahlavan, A ; Momtazpour, M ; Goudarzi, M ; Sharif University of Technology
    The growth in number of data centers and its power consumption costs in recent years, along with ever increasing process variation in nanometer technologies emphasizes the need to incorporate variation-aware power reduction strategies in early design stages. Moreover, since the power characteristics of identically manufactured servers vary in the presence of process variation, their position in the data center should be optimally determined. In this paper, we introduce two heuristic variation-aware server placement algorithm based on power characteristic of servers and heat recirculation model of data center. In the next step, we utilize an Integer Linear Programming (ILP) based... 

    Femtocell base station clustering and logistic smooth transition autoregressive-based predicted signal-to-interference-plus-noise ratio for performance improvement of two-tier macro/femtocell networks

    , Article IET Signal Processing ; Volume 10, Issue 1 , 2016 , Pages 1-11 ; 17519675 (ISSN) Lotfollahzadeh, T ; Kabiri, S ; Kalbkhani, H ; Shayesteh, M. G ; Sharif University of Technology
    Institution of Engineering and Technology 
    The aim of this study is to improve the performance of two-tier macro/femtocell networks using a power control approach. In wireless networks, power control plays an important role in improving a number of performance parameters such as co-channel interference and outage probability reduction, throughput increasing, and power saving. This study explores the evolution of centralised power control algorithm based on femtocell base station (FBS) clustering and predicted signal-to-interference-plus-noise ratio (SINR) of users. To reduce the computational complexity of centralised algorithm, dense deployed femtocells are considered in different clusters. In this case, femtocells inside one... 

    Outage probability and power allocation of amplify and forward relaying with channel estimation errors

    , Article IEEE Transactions on Wireless Communications ; Volume 10, Issue 1 , November , 2011 , Pages 124-134 ; 15361276 (ISSN) Tabataba, F. S ; Sadeghi, P ; Pakravan, M. R ; Sharif University of Technology
    This paper studies the statistical properties of the signal-to-noise ratio (SNR) of the dual-hop relaying link in a cooperative wireless communication system in the presence of channel estimation errors for fixed-gain (FG) and variable-gain (VG) relays. The SNR expression is derived and three different analytical approaches with different simplifying assumptions are proposed to obtain the probability distribution function of the SNR and the outage probability in each mode. All but one approach result in closed-form expressions for the outage probability. The simplest approach in each mode has been used to find an optimum power allocation scheme for pilot and data symbols transmission at the...