Chen Xinqiao, Li Zhihan, Ba Wenyao, Dai Siyuan, Liang Jingjing, Xiao Huaibao
School of Information and Communication Engineering, Communication University of China, Beijing 100024, China.
Heliyon. 2023 Mar 2;9(3):e14221. doi: 10.1016/j.heliyon.2023.e14221. eCollection 2023 Mar.
An novel method to generate 40-tupling frequency millimeter (MMW) based on the remodulation of MZMs and a novel radio over fiber (ROF) system to transmit the generated MMW are proposed. At the central station (CS), the ±4th order sidebands generated by two Mach-Zehnder modulators (MZMs) in parallel are used as the optical carriers for the remodulation. The radio frequency (RF) signal for the remodulation can be generated by injecting the ±4th order sidebands in the photodetector (PD). The main components in the signal after remodulation are ±4th, ±12th and ±20th order sidebands, among them, the +20th sideband is filtered out by a fiber Bragg grating (FBG). After the +20th order sideband is modulated with the downlink data, the ±20th order sidebands are combined again and transmitted to the base station (BS) by optical fiber. At the BS, a part of -20th order sideband is filtered out with a FBG, and with which the uplink data is modulated on it and sent back to the CS for carrier wave reuse. The 40-tupling frequency MMW signal with downlink data is generated by beating the output signal from FBG in the PD. In the case of data rate is 2.5G/bps and the bit error rate is less than 10, the transmission distance can exceed 90 km, the power penalty of the uplink and downlink is less than 1 dB and 0.29 dB, respectively. Our scheme has simple structure, high frequency multiplier factor, it has important application prospects in MMW technology.
