269 research outputs found
PLANNING TO PLEASE CUSTOMERS
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
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
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
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
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 . Here, is the number of
symbols transmitted within one fading block, and 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 . Since the
capacity pre-log corresponding to symbol-rate sampling is , 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
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
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