Đang chuẩn bị liên kết để tải về tài liệu:
Ultra Wideband Part 4

Tham khảo tài liệu 'ultra wideband part 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 84 Ultra Wideband Fiber-optic communication system can be divided into three groups i point-to-point links ii distribution networks iii local area networks LAN Agrawal 2002 . In particular the UROOF concept enables the transmission of UWB radio frequency RF signals over optical fibers by superimposing the UWB RF signals of several GHz on the optical CW carrier Ran 2009 Yao 2009 . UROOF applications are related to the short-haul case Ran 2009 . UROOF technology can be successfully applied in WPAN security systems with a large number of sensors and cameras equipped with UWB and broadband multimedia Ran 2009 . In a typical application of a broadband indoor system UWB signals are generated and encoded in a central office and distributed over optical fiber to the access points where the UWB signals are down-converted from the optical domain to the electrical domain and the detected UWB signals radiate to free space Ran 2009 Yao 2009 . UROOF technology has the following advantages Ran 2009 Yao 2009 1. The conversion process becomes transparent to the UWB modulation method. 2. The high costs of additional electronic components required for synchronization and other processes can be avoided. 3. The integration of all the RF and optical transmitter receiver components on a single chip is possible. For the sake of definiteness we consider the analog optical communication systems which permit the transmission of multilevel modulated radio signals as an envelope of the optical carrier over the optical fiber Ran 2009 . 5. UWB Analog Optical Link In this section we briefly discuss the problems related to the high-performance optical links in UROOF communication systems. UWB high-speed optical link includes E O converter an optical fiber and optical electrical O E converter Ran 2009 . We need to carry out the modulation of an optical signal or up-conversion at the input of the UROOF system and separation of the electrical signal envelope from the optical carrier or .