Four Sub-Channel Single Sideband Generation of Vector mm-Wave Based on an I/Q Modulator

Wen Zhou,Kaihui Wang,Li Zhao,Jiao Zhang

doi:10.1109/jphot.2019.2932952

Abstract

In this paper, a novel scheme to generate multichannel single sideband (SSB) optical signals enabled by one single I/Q modulator based on digital signal processing (DSP) is proposed, which is more flexibility and stability for the future 5G broadband access network instead of complex multiple lasers construction. Four sub-channels carrying different vector quadrature amplitude modulated (QAM) data are modulated to the upper sideband (USB) by I/Q modulation, while the vector unmodulated RF signal is located at the lower sideband (SSB) of the suppressed center carrier. They are used to generate four different mm-wave carriers after heterodyne beating. Due to the imbalance effect of I and Q components from the I/Q modulator, we also optimize the frequency of USB and LSB to reduce the crosstalk between the USB and LSB signal. The experimental results indicate that four-channel QPSK (2 × 2 × 4 = 16 Gbit/s) and 16-QAM (2 × 4 × 4 = 32 Gbit/s) signals with 5 GHz channel spacing at Q-band can be transmitted over 80 km single-mode-fiber 28 and 0.5 m wireless link without dispersion compensation.

Highlights

The consumer demand for the mobile network keeps steady and rapid growth, with conservative estimates doubling year upon year since 2010
Due to the imbalance effect of I and Q components from the I/Q modulator, we optimize the frequency of upper sideband (USB) and lower-side band (LSB) to reduce the crosstalk between the USB and LSB signal
The digital multichannel driving signal for I and Q inputs is produced via software-based digital signal processing (DSP) instead of a complex transmitter adopting multi lasers, the system structure is significantly simplified with high reliability

Summary

Introduction

The consumer demand for the mobile network keeps steady and rapid growth, with conservative estimates doubling year upon year since 2010. The future 5G cellular network aims to develop a novel mobile network architecture that provides broadband access with high flexibility and reliability in a resource efficient way to handle tremendous explosion of the traffic [1]. Millimeter-wave (mm-wave) is enabling a broad bandwidth for the generation 5G mobile communication network, which will handle tens of Gigabits per second peak throughputs [2]–[10]. Wavelength division multiplexing (WDM) is the promising way to further enhance the capacity [11], [12]. In order to allocate a number of wavelength channels, the cost and the complexity as well as the system stability inherent to the transmitters employing multi individual light resources will be a critical problem [18]

Methods

Results

Conclusion