Notwithstanding its infancy, wireless mesh networking (WMN) is a hot and
growing field. Wireless mesh networks began in the military, but have since
become of great interest for commercial use in the last decade, both in local
area networks and metropolitan area networks. The attractiveness of mesh
networks comes from their ability to interconnect either mobile or fixed
devices with radio interfaces, to share information dynamically, or simply to
extend range through Multi-Hopping.
Notwithstanding its infancy, wireless mesh networking (WMN) is a hot and
growing field. Wireless mesh networks began in the military, but have since
become of great interest for commercial use in the last decade, both in local
area networks and metropolitan area networks. The attractiveness of mesh
networks comes from their ability to interconnect either mobile or fixed
devices with radio interfaces, to share information dynamically, or simply to
extend range through Multi-Hopping.
同步技術(shù)是跳頻通信系統(tǒng)的關(guān)鍵技術(shù)之一，尤其是在快速跳頻通信系統(tǒng)中，常規(guī)跳頻通信通過同步字頭攜帶相關(guān)碼的方法來實(shí)現(xiàn)同步，但對(duì)于快跳頻來說，由于是一跳或者多跳傳輸一個(gè)調(diào)制符號(hào)，難以攜帶相關(guān)碼。對(duì)此引入雙跳頻圖案方法，提出了一種適用于快速跳頻通信系統(tǒng)的同步方案。采用短碼攜帶同步信息，克服了快速跳頻難以攜帶相關(guān)碼的困難。分析了同步性能，仿真結(jié)果表明該方案同步時(shí)間短、虛警概率低、捕獲概率高，同步性能可靠。
Abstract:
Synchronization is one of the key techniques to frequency-hopping communication system， especially in the fast frequency hopping communication system. In conventional frequency hopping communication systems， synchronization can be achieved by synchronization-head which can be used to carry the synchronization information， but for the fast frequency hopping， Because modulation symbol is transmitted by per hop or Multi-Hop， it is difficult to carry the correlation code. For the limitation of fast frequency hopping in carrying correlation code， a fast frequency-hopping synchronization scheme with two hopping patterns is proposed. The synchronization information is carried by short code， which overcomes the difficulty of correlation code transmission in fast frequency-hopping. The performance of the scheme is analyzed， and simulation results show that the scheme has the advantages of shorter synchronization time， lower probability of false alarm， higher probability of capture and more reliable of synchronization.
This exercise is aimed at exploring how rate control and adaptation of carrier sense threshold can affect spatial reuse (and hence aggregate throughput) in a Multi-Hop network.
LTE-Advanced becomes a truly global standard for 4G cellular communications.
Relay, as one of the key technologies of LTE-Advanced, can significantly extend
the coverage, and improve the system throughput. LTE-A standards and tech-
nologies were described in several recent books where the limited pages for relay
feature prevent the detailed explanations of the technology. In this book, we tried
to provide an in-depth description of LTE-A relay development. More specifically,
significant portions are spent on relay channel modeling and potential technologies
during the study item phase of the development, although some of those tech-
nologies, such as Type 2 cooperative relay, Multi-Hop relay, relay with backhaul of
carrier aggregation, were not standardized in Release 10 LTE.
A mobile ad-hoc network (MANET) is formed by multiple moving nodes
equipped with wireless transceivers. The mobile nodes communicate with
each other through Multi-Hop wireless links, where every node can transmit
and receive information. Mobile ad-hoc networks have become increasingly
important in areas where deployment of communications infrastructure is
difficult.
Radio frequency identification (RFID) and Wireless sensor networks (WSN) are
the two key wireless technologies that have diversified applications in the present
and the upcoming systems in this area. RFID is a wireless automated recognition
technology which is primarily used to recognize objects or to follow their posi-
tion without providing any sign about the physical form of the substance. On the
other hand, WSN not only offers information about the state of the substance
and environment but also enables Multi-Hop wireless communications.
