269 research outputs found

    PLANNING TO PLEASE CUSTOMERS

    Get PDF
    Abstract- The achievable rate of a coherent coded modulation (CM) digital communication system with data-aided channel estimation and a discrete, equiprobable symbol alphabet is derived under the assumption that the system operates on a flat fading MIMO channel and uses an interleaver to combat the bursty nature of the chan-nel. It is shown that linear minimum mean square er-ror (LMMSE) channel estimation directly follows from the derivation, and links average mutual information to the channel dynamics. Based on the assumption that known training symbols are transmitted, the achievable rate of the system is optimized with respect to the amount of training information needed. I

    Automation of technological preparation of metal working on heavy machine tools

    Get PDF
    The programs for selection of the cutting tools construction and cutting regimes are working in unrestricted surroundings elaborate of addition SharpDevelop in language C#. By the appendix of Cosmos of the program SolidWorks the areas of plate break-age and tensions distributing arising up in it at the different values of cutting force are certain. Based on the conducted researches of durability the rational structural parameters of collapsible chisels, in particular, thickness of plate are grounded that provides the increase of efficiency of treatment of details a hard-alloy instrument on the heavy machine tool

    On Complexity, Energy- and Implementation-Efficiency of Channel Decoders

    Full text link
    Future wireless communication systems require efficient and flexible baseband receivers. Meaningful efficiency metrics are key for design space exploration to quantify the algorithmic and the implementation complexity of a receiver. Most of the current established efficiency metrics are based on counting operations, thus neglecting important issues like data and storage complexity. In this paper we introduce suitable energy and area efficiency metrics which resolve the afore-mentioned disadvantages. These are decoded information bit per energy and throughput per area unit. Efficiency metrics are assessed by various implementations of turbo decoders, LDPC decoders and convolutional decoders. New exploration methodologies are presented, which permit an appropriate benchmarking of implementation efficiency, communications performance, and flexibility trade-offs. These exploration methodologies are based on efficiency trajectories rather than a single snapshot metric as done in state-of-the-art approaches.Comment: Submitted to IEEE Transactions on Communication

    Audio books as a method of learning the English language

    Get PDF
    The purpose of the article is to introduce some information about the method of learning a foreign language using audio books to the reader. The author draws attention to different ways of information perception (auditory, visual and kinesthetic) to let the reader evaluate the effectiveness of this learning method. Much attention is focused on the algorithm of learning English using an audio book. As an example, a famous book «The Adventures of Tom Sawyer» by Mark Twain is examined. In conclusion, the author underlines the advantages and disadvantages of the method. Цель данной статьи заключается в том, чтобы познакомить читателя с техникой изучения иностранного языка при помощи аудиокниг. Автор обращает внимание на различные способы восприятия информации (слуховой, зрительный и кинестетический), чтобы увидеть, насколько этот метод обучения может быть эффективным. Большое внимание уделяется алгоритму изучения английского языка с помощью аудиокниги. В качестве примера приводится знаменитая книга Марка Твена "Приключения Тома Сойера". В заключении автор указывает на преимущества и недостатки данного метода

    Oversampling Increases the Pre-Log of Noncoherent Rayleigh Fading Channels

    Get PDF
    We analyze the capacity of a continuous-time, time-selective, Rayleigh block-fading channel in the high signal-to-noise ratio (SNR) regime. The fading process is assumed stationary within each block and to change independently from block to block; furthermore, its realizations are not known a priori to the transmitter and the receiver (noncoherent setting). A common approach to analyzing the capacity of this channel is to assume that the receiver performs matched filtering followed by sampling at symbol rate (symbol matched filtering). This yields a discrete-time channel in which each transmitted symbol corresponds to one output sample. Liang & Veeravalli (2004) showed that the capacity of this discrete-time channel grows logarithmically with the SNR, with a capacity pre-log equal to 1Q/N1-{Q}/{N}. Here, NN is the number of symbols transmitted within one fading block, and QQ is the rank of the covariance matrix of the discrete-time channel gains within each fading block. In this paper, we show that symbol matched filtering is not a capacity-achieving strategy for the underlying continuous-time channel. Specifically, we analyze the capacity pre-log of the discrete-time channel obtained by oversampling the continuous-time channel output, i.e., by sampling it faster than at symbol rate. We prove that by oversampling by a factor two one gets a capacity pre-log that is at least as large as 11/N1-1/N. Since the capacity pre-log corresponding to symbol-rate sampling is 1Q/N1-Q/N, our result implies indeed that symbol matched filtering is not capacity achieving at high SNR.Comment: To appear in the IEEE Transactions on Information Theor

    A Scalable VLSI Architecture for Soft-Input Soft-Output Depth-First Sphere Decoding

    Full text link
    Multiple-input multiple-output (MIMO) wireless transmission imposes huge challenges on the design of efficient hardware architectures for iterative receivers. A major challenge is soft-input soft-output (SISO) MIMO demapping, often approached by sphere decoding (SD). In this paper, we introduce the - to our best knowledge - first VLSI architecture for SISO SD applying a single tree-search approach. Compared with a soft-output-only base architecture similar to the one proposed by Studer et al. in IEEE J-SAC 2008, the architectural modifications for soft input still allow a one-node-per-cycle execution. For a 4x4 16-QAM system, the area increases by 57% and the operating frequency degrades by 34% only.Comment: Accepted for IEEE Transactions on Circuits and Systems II Express Briefs, May 2010. This draft from April 2010 will not be updated any more. Please refer to IEEE Xplore for the final version. *) The final publication will appear with the modified title "A Scalable VLSI Architecture for Soft-Input Soft-Output Single Tree-Search Sphere Decoding
    corecore