Full-duplex lightwave transport systems employing phase-modulated RoF and intensity-remodulated CATV signals

Abstract

A full-duplex lightwave transport system employing phase-modulated radio-over-fiber (RoF) and intensity-remodulated CATV signals in two-way transmission is proposed and experimentally demonstrated. The transmission performances of RoF and CATV signals are investigated in bidirectional way, with the assistance of only one optical sideband and optical single sideband (SSB) schemes at the receiving sites. The experimental results show that the limitation on the optical modulation index (OMI) of the downlink RoF signal can be relaxed due to the constant intensity of phase modulation scheme. Impressive transmission performances of bit error rate (BER), carrier-to-noise ratio (CNR), composite second-order (CSO), and composite triple-beat (CTB) were obtained over two 20-km single-mode fiber (SMF) links. This proposed system reveals an outstanding one with economy and convenience to be installed.

Multifunctional photonic broadband RF memory for complex electronic jamming

“…With the application of complex radar waveforms in radar detection, the pulse widths of radar signals are generally from hundreds of nanoseconds to hundreds of microseconds, and the frequencies of pulse modulation waveforms cover L band to Ku band, even to Ka band. In order to jam radar signals which have complex modulation waveforms, electronic jammers need to develop diverse jamming modes, such as reconfiguration of pulse width, bandwidth and storage time [1,2], and should also have rapid response time and high fidelity to acquire high success rate of jamming [3][4][5]. When the electronic jammer pulls in/off the range or velocity gate, the first RF pulse signal generated by jammer and the RF pulse signal generated by radar should enter into the gate at the same time, thus the electronic jammers should not only store the input signals with complete pulse width, but also have rapid enough response time [6].…”

Based on FP LDs with split band technique in two-channel fiber optical CATV transport system

“…These parameters can be seriously degraded by stimulated Brillouin scattering (SBS), stimulated Raman scattering (SRS), and fiber dispersion effects in 1550-nm fiber optical CATV transport systems. Several ways have been proposed to solve these problems such as employing an externally modulated transmitter and differential detection through two fiber links [3], using external light injection locking or sideband filtering techniques [4,5], the CSO and CTB performances can be improved [6][7][8]. Nevertheless, an expensive externally modulated transmitter as well as sophisticated differential detection, external light injection locking, and sideband filtering techniques are required.…”

“…As the user receives the channels transmitted from the headend, an ID code verification will be excuted to verify whether the channel is the user desired. Meanwhile, to avoid the interference of other channels, we choose two channels with different frequencies by using two converters at each moment which avoid the expensive equipment and complex systems that are required by the system of full channel loading [3][4][5][6][7][8][9]. Fig.…”

“…5 show the measured CNR, CSO and CTB values under NTSC channel number of systems I and II, as well as the schematic CNR, CSO and CTB definitions. CNR can be expressed as:…”

Nonlinear distortion evaluation in a directly modulated distributed feedback laser diode-based fiber-optic cable television transport system

“…[1][2][3][4][5] Therefore, the transmission quality of such a system has been defined and regulated, which basically determines the signal-receiving quality of the system based on the following three parameters: carrier-to-noise ratio (CNR), composite second order (CSO), and composite triple beat (CTB). 6 Both noise and nonlinear effects in the fiber-optic CATV transmission system are mostly caused by active components but rarely by passive components.…”