This paper investigates the maximal channel coding rate achievable at a given blocklength and error probability. For general classes of channels new achievability and converse bounds are given, which are tighter than existing bounds for wide ranges of parameters of interest, and lead to tight approximations of the maximal achievable rate for blocklengths n as short as 100. It is also shown analytically that the maximal rate achievable with error probability ? isclosely approximated by C - ?(V/n) Q-1(?) where C is the capacity, V is a characteristic of the channel referred to as channel dispersion , and Q is the complementary Gaussian cumulative distribution function.

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Channel Coding Rate in the Finite Blocklength Regime

An apparatus and method for a digital filing system which uses indexing (703), scanning (775), image storage (785) and image retrieval (795) as part of the efficient management of paper-based information. The preferred embodiments of the present invention provide easy and effective management of paper documents, transforming them into electronic documents using a system which incorporates many existing office resources. The proposed system implements a desktop solution for digital filing, which can be made available to each worker. In one embodiment of the present invention, an individual has complete control over the electronic storage and retrieval of their documents from a standard desktop computer, using a standard web browser application. Uniquely, the digital filing system of the present invention also allows users to index and label documents (760) prior to scanning/imaging (775) by using a dedicated desktop labeling mechanism.

Apparatus and method for digital filing

Aspects of the subject disclosure may include, for example, receiving, by a feed point of a dielectric antenna, electromagnetic waves from a dielectric core coupled to the feed point without an electrical return path, where at least a portion of the dielectric antenna comprises a conductive surface, directing, by the feed point, the electromagnetic waves to a proximal portion of the dielectric antenna, and radiating, via an aperture of the dielectric antenna, a wireless signal responsive to the electromagnetic waves being received at the aperture. Other embodiments are disclosed.

Method and apparatus for coupling an antenna to a device

A distributed antenna and backhaul system provide network connectivity for a small cell deployment. Rather than building new structures, and installing additional fiber and cable, embodiments described herein disclose using high-bandwidth, millimeter-wave communications and existing power line infrastructure. Above ground backhaul connections via power lines and line-of-sight millimeter-wave band signals as well as underground backhaul connections via buried electrical conduits can provide connectivity to the distributed base stations. An overhead millimeter-wave system can also be used to provide backhaul connectivity. Modules can be placed onto existing infrastructure, such as streetlights and utility poles, and the modules can contain base stations and antennas to transmit the millimeter-waves to and from other modules.

Backhaul link for distributed antenna system

A distributed antenna system is provided that frequency shifts the output of one or more microcells to a 60 GHz or higher frequency range for transmission to a set of distributed antennas. The cellular band outputs of these microcell base station devices are used to modulate a 60 GHz (or higher) carrier wave, yielding a group of subcarriers on the 60 GHz carrier wave. This group will then be transmitted in the air via analog microwave RF unit, after which it can be repeated or radiated to the surrounding area. The repeaters amplify the signal and resend it on the air again toward the next repeater. In places where a microcell is required, the 60 GHz signal is shifted in frequency back to its original frequency (e.g., the 1.9 GHz cellular band) and radiated locally to nearby mobile devices.

Remote distributed antenna system

Introduction. Fundamentals of Electromagnetic Waves. Dielectric Waveguide. Dielectric Sectoral and Pyramidal Horns. Dielectric Cylinder. Dielectric Cone. Dielectric Lenses.

Solid Dielectric Horn Antennas

An approximate theory for the propagation and radiation characteristics of dielectric cones is developed. A formulation in terms of spherical modes is used in the interior of the cone, and boundary conditions are applied so that the field exterior to the cone has surface-wave properties. The propagation and radiation characteristics are found to resemble closely those for corrugated horns, and experimental results support the theoretical predictions.

Antennas employing conical dielectric horns. Part 1: Propagation and radiation characteristics of dielectric cones

From the Publisher:
After a period when optical links appeared to become the solution to all transmission problems, the ongoing revolution in the telecommunications sector and the advances in technology have brought microwave links back to center stage.
* Detailed comparison of ITU (International Telecommunications Union) and North American frequency hierarchies, an important topic that has been inadequatly covered
* Contains end -of-chapter problem sets and a solutions manual Includes extensive discussion of error control codes

Microwave Radio Links: From Theory to Design

A design theory is presented for Cassegrain antennas employing dielectric-cone feeds. A modal approach is used to describe the aperture field over the subreflector, while a ray-optics method is employed to determine the sub-reflector profile and main-reflector aperture distribution. Experiments have been made with antennas designed for operation over bands centred near 11 and 18 GHz, and results are in generally good agreement with theory. These antennas are shown to have high efficiency, good main-beam symmetry and low mutual coupling.

Antennas employing conical-dielectric horns. Part 2: The Cassegrain antenna

In this paper, a thorough study of radiowave propagation phenomena in the presence of wildfires, is presented. Electrical modelling of a fire environment based on computational fluid dynamics is revisited. Modelling of the fire phenomena, in terms of refractive index and combustion of cold plasma, lays the foundation for considering the fire environment as a propagation medium. Electrical models are formulated to provide means of calculating propagation characteristics based on thermalionisation, to create a plasma surface under fire environments and, thus, to determine the excess loss arising in the burning region. This paper presents initial results for single trees under fire at 385 MHz, envisaged to assist the identification of radio exclusion zones in real-time during wildfires, in mission critical applications.

Carlos Salema

Papers

Solid Dielectric Horn Antennas

Antennas employing conical dielectric horns. Part 1: Propagation and radiation characteristics of dielectric cones

Microwave Radio Links: From Theory to Design

Antennas employing conical-dielectric horns. Part 2: The Cassegrain antenna

Radiowave Propagation Modelling in the Presence of Wildfires: Initial Results