Review on the Millimeter-Wave Generation Techniques Based on Photon Assisted for the RoF Network System

Abstract

With the development trend of wireless and broadband in the communication link and even the whole information industry, the demand of high-frequency microwave bandwidth has been increasing. The RoF network system solves the problem of spectrum congestion in low-frequency band by providing an effective technology for the distribution of high-frequency microwave signals over optical fiber links. However, the traditional mm-wave generation technique is limited by the bandwidth of electronic devices. It is difficult to generate high-frequency and low-phase noise mm-wave signals with pure electrical components. The mm-wave communication technology based on photon assisted can overcome the bandwidth bottleneck of electronic devices and provide the potential for developing the low-cost infrastructure demand of broadband mobile services. This paper will briefly explain the characteristics of the RoF network system and the advantages of high-frequency mm-wave. Then we, respectively, introduce the modulation schemes of RoF mm-wave generation based on photon assisted including directly modulated laser (DML), external modulation, and optical heterodyne. The review mainly focuses on a variety of different mm-wave generation technologies including multifrequency vector mm-wave. Furthermore, we list several approaches to realize the large capacity data transmission techniques and describe the digital signal processing (DSP) algorithm flow in the receiver. In the end, we summarize the RoF network system and look forward to the future.

Dual-wavelength fiber-laser-based transmission of millimeter waves for 5G-supported Radio-over-Fiber (RoF) links

“…The designed laser output shows a good power uniformity with power fluctuations of 0.32 dB and generates stable mmW waves of 56 GHz with wavelength fluctuations of 0.03 over an observation period of 60 minutes. Subsequently, a phase-stable RF spectrum is achievable as the minimal wavelength-fluctuations are recorded in this work without using any optical modulator, which causes instability in laser-based mmW wave generations due to fluctuations in DC biasing [36]. Moreover, the proposed EDFL laser is a simple and inexpensive structure contrast with without using any photonic-crystal fiber [37].…”

“…The upper sideband is filtered out with an optical bandpass filter (OBPF) of center-wavelength of 1559.40 nm for obtaining the lower sideband of the OFDM signals (LSB-OFDM). This LSB-OFDM signal is multiplexed with the unmodulated carrier signal of arm two via 1:2 MUX and then transmitted over the standard singlemode fiber (SSMF) of 20 Km [36]. For a multi-channel system or to accommodate more than one channel simultaneously over the attenuating fiber links for realizing the wavelength division multiplex (WDM) system, there is a probability of signal attenuation due to signal demultiplexing components.…”

Path Loss Measurements and Model Analysis in an Indoor Corridor Environment at 28 GHz and 38 GHz

“…The system was also able to solve the problem of bandwidth in electronic devices, allowing for the growth of low-cost infrastructure demand for broadband mobile devices. The main disadvantage of this strategy is that it tends to fail as distance and communication capabilities grow [ 30 , 31 , 32 ]. Chittimoju and Yalavarthi [ 33 ] conducted a complete assessment of millimeter wave communications, including some of the benefits and uses.…”

Research progress of optical millimeter wave generation technology in RoF system

“…The superiority of RoF technology has gradually been recognized and accepted by everyone. As people's demand for wireless broadband is increasing, and operators are more inclined to the construction of wireless communications, people have turned their attention to the high-frequency millimeter-wave band with more abundant spectrum resources [3] .…”