We propose a new transmission scheme of multi-rate low density generator matrix (LDGM) code suitable for optical satellite communications. Since the proposed scheme doesn't utilize a preamble transmission of the r...
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We propose a new transmission scheme of multi-rate low density generator matrix (LDGM) code suitable for optical satellite communications. Since the proposed scheme doesn't utilize a preamble transmission of the rate information nor the repeat request scheme, a long feedback delay in the satellite link and a decrease of transmission efficiency can be avoided. Then, an adaptive rate transmission only with forward error correction (FEC) is achieved and the transmitter can choose the quality or the rate-efficiency of transmission from the transmitter-side state. In the receiver, an exact rate-decision and decoding are conducted without the preamble. It is shown that the proposed scheme is effective in the satellite-to-ground optical link by the computer simulations.
Ultra-wideband (UWB) technology is a new concept in wireless short-range communication. It has numerous advantages that are resulted in producing different new products in various applications. This technology uses ve...
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ISBN:
(纸本)9781457703898
Ultra-wideband (UWB) technology is a new concept in wireless short-range communication. It has numerous advantages that are resulted in producing different new products in various applications. This technology uses very short duration pulses hence occupies very large transmission bandwidth. This phenomenon may cause harmful interference in the existing wireless devices. The main objective of this study is to evaluate the effective parameters in ultra-wideband communication for indoor short-range devices. In this regard, two commercial UWB devices are utilized and effects of these devices in different experimental configurations are investigated. Three configurations including the effects of distance, narrowband spectrum, and another UWB device on bit error rate performance are evaluated. The results of the performed experiments showed the stability and amenability of the UWB technology to be used in multiple UWB devices.
Despite the large size of most communication and transportation systems, there are short paths between nodes in these networks which guarantee the efficient information, data and passenger delivery; furthermore these ...
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Despite the large size of most communication and transportation systems, there are short paths between nodes in these networks which guarantee the efficient information, data and passenger delivery; furthermore these networks have a surprising tolerance under random errors thanks to their inherent scale-free topology. However, their scale-free topology also makes them fragile under intentional attacks, leaving us a challenge on how to improve the network robustness against intentional attacks without losing their strong tolerance under random errors and high message and passenger delivering capacity. Here We propose two methods （SL method and SH method） to enhance scale-free network＇s tolerance under attack in different conditions.
It is getting important that applies social network of collaborative learning to intelligent distance learning system. In this paper, we used the Rule-Space Model to infer reasonable Blue-Red trees of learning perform...
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ISBN:
(纸本)9781849192088
It is getting important that applies social network of collaborative learning to intelligent distance learning system. In this paper, we used the Rule-Space Model to infer reasonable Blue-Red trees of learning performance and their definitions. We can derive nine learning groups of social network grouping algorithms and classify particular Blue-Red Trees that belong to specific learning group from previous definitions. They include the general formula for one-to-one complementary collaborative learning group algorithms of strong learning and illustration distribution. Therefore, we use these algorithms to build a social network learning system and social network learning methods with learning performance of Blue-Red trees. Finally, an example for a course with the Rule-Space Model analysis of learning objects is illustrated and proved. From this example, they can be created thirty-six learning performances of Blue-Red trees that are grouped under nine learning groups of social network and inferred one-to-one complementary collaborative learning group algorithms of strong learning. So, the algorithms within the system will recommend those specific Blue-Red trees that satisfy one-to-one complementary collaborative learning group of strong learning.
The remote host fault detecting for FTTH-PON using web-based is demonstrated. Our solution works on a standard local area network (LAN) using a specially designed hardware interfaced with a microcontroller integrated ...
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This paper presents and experimentally demonstrates a MATLAB-based graphical user interface (GUI) namely Smart Access network - Testing, Analyzing and Database (SANTAD), which will be installed at central office (CO) ...
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This paper reports a novel physical layer monitoring technique called Centralized Failure Detection System (CFDS) based on the use of an optical time domain reflectometry (OTDR) and integrated with inexpensive additio...
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This paper calculates the optical power budget and power margin for designing a conventional passive optical network (PON)-based Fiber-To-the-Home (FTTH) and Intelligent Fiber-To-the-Home (i-FTTH) with different link ...
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Transition metal-doped ZnS materials have received broad attention due to their well-known performance in electronics and optics. It has been observed previously by other researchers that Mn is one of interesting dopa...
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