Система Импульсной Радиосвязи С Использованием Сверхширокополосных Сигналов-Триплет

Abstract

Intensive development of modern wirelesscommunications such as the systems of wireless access toInternet and local network systems operating in indoorenvironment provoked interest in study the features andmodels of wireless communication channels. The presence ofthe walls; partitions; furniture; radio electronic equipment;people and other objects inside the building create intricateenvironment for the propagation of radio waves. The maineffects observed in the propagation of radio waves inside thepremises are multipath due to multiple reflections of radiowaves from walls and other objects; diffraction on thenumerous sharp edges of objects located inside the room; andscattering of radio waves. These effects create intricateinterference structure of the electromagnetic field; whichvaries greatly when people and other objects move.UWB communication systems are characterized by highdata rates; low cost; multipath immunity; and large toleranceto interfering legacy systems. In recent years; UWBtechnologies have been rapidly developingPerformance of all known communication systems usingenergy-based receivers largely depends on the transmittedsignal energy; i.e. decision making is carried out at thematched filter output by estimation of signal energy. Due tothis principal peculiarity; deep fading attenuating of receivedsignal magnitude provokes considerable decreasing of signalenergy and; as consequence; performance provided bycommon energy-based decision making strategy is worsen.Suggested strategy exploiting for building novel UWBcommunication systems is based on the features of higher-order spectra. Performance provided by exploitingsuggested bispectrum-organized triplet-signals andbispectrum-based decision making for detection anddiscrimination the triplets depends on given phase couplingrelationships contained in triplet-signals. Because of this;despite considerable attenuating of triplet-signal amplitude;phase coupling information remains to be preserved for truetriplet-signals discrimination and correct decision making fordata passed through the fading wireless channel

Амфоры Типа 27 По Классификации В.В. Крапивиной Из Тиры

“…Крапивиной эти сосуды могли использовать для перевозки соленой рыбы 45 , однако они были более вместительными. Объем таких сосудов составляет около 135 литров 46 , хотя встречаются небольшие экземпляры емкостью от 30 до 60 литров 47 . В отличие от амфор типа 27 по В.В.…”