The influence of fiber dispersion on the code form of the optical mm-wave signal generated by single sideband intensity-modulation

Influence of the modulation index of Mach–Zehnder modulator on RoF link with ASK millimeter-wave signal

“…3. For the optical carrier, the code ''0'' and ''1'' are represented by the amplitude 1 and J 0 (m h ), respectively, namely, the code ''1'' is denoted by the dip on the high level, which is greatly different from the SSB optical mmwave signal that we have reported in [4]. If the modulation index is low, J 0 (m h )E1, the dip is much low, namely, the amplitudes of the pulse representing the code ''0'' and ''1'' have little difference, as shown in Fig.…”

“…Usually, the Mach-Zehnder modulator (MZM) and electro-absorption modulator (EAM) are used to implement this. However, different prototypes of MZM can generate the optical mm-wave with different spectra, such as double sideband (DSB), optical carrier suppression (OCS), and single sideband (SSB), while each of them has different immunity capacity for the fiber dispersion [3][4][5][6]. The DSB optical mm-wave suffers not only from the fading effect but also from the time shift of the code caused by the sidebands' walk-off [3].…”

“…The DSB optical mm-wave suffers not only from the fading effect but also from the time shift of the code caused by the sidebands' walk-off [3]. Although the OCS optical mm-wave and the SSB optical mm-wave with the signal carried by both the optical carrier and its sideband is immune to fading, time shift of the code limits its transmission [4][5][6]. The SSB optical mm-wave with the signals carried only by optical sideband can overcome both the fading effect and the time shift of the code [7].…”

A radio‐over‐fiber system with photonics generated OFDM signals by using directly modulated laser

“…In radioover-fiber (ROF) system, a central station (CS) is connected to many functionally simple base stations (BSs) via optical fiber. Almost all the processions including modulation, demodulation, coding, routing are performed at the CS [1][2][3][4][5]. The main function of BS is to realize optical/electrical conversion and broadcasting by antenna.…”

“…However, over the designated UWB frequency band, there are existing wireless local area network (WLAN) operating bands such as the 5.2 GHz (5150 -5350 MHz) and 5.8 GHz (5725-5825 MHz) bands, which may cause interference with UWB operations. To overcome electromagnetic interference between UWB systems and WLAN systems, various UWB antennas with a notch function have been developed for UWB communication systems [1][2][3][4][5]. The conventional methods to achieve a notched band are put parasitic elements near the printed monopole, playing a role as resonance cell to reject the limited band [6,7], by eroding U-like slots on the patch [8,9], or introduced a resonance filter in the feed line [10].…”