40 Gb/s W-band (75–110 GHz) 16-QAM radio-over-fiber signal generation and its wireless transmission

Abstract

The generation of a 40-Gb/s 16-QAM radio-over-fiber (RoF) signal and its demodulation of the wireless signal transmitted over free space of 30 mm in W-band (75-110 GHz) is demonstrated. The 16-QAM signal is generated by a coherent polarization synthesis method using a dual-polarization QPSK modulator. A combination of the simple RoF generation and the versatile digital receiver technique is suitable for the proposed coherent optical/wireless seamless network.

Full-duplex RoF link with broadband mm-wave signal in W-band based on WDM-PON access network with optical mm-wave local oscillator broadcasting

“…Moreover, it has become a potential candidate to solve the bit rate mismatch between the wireless and fiber communications [11]. Recently, many institutions have done research on W-band mm-wave signal generation and transmission [12][13][14][15][16][17][18][19][20][21]. In [12][13][14][15][16], two independent lasers are heterodyne mixed to obtain the W-band signal at BS.…”

“…Even if the very narrow line-width lasers are used, the train sequence, cyclic prefix and suffix, or complex phase estimation and compensation algorithms are required to resist the phase noise. Another scheme to generate the W-band signal is proposed by Kanno et al [17][18][19], in which, a dual-tone optical mm-wave signal in W-band is generated based on frequency multiplication technology. In these schemes, only a dual-parallel Mach-Zehnder modulator is utilized and the frequency of the generated W-band mm-wave signal is quite stable, but it is limited by the requirement of the high-bandwidth and expensive optical components.…”

Wireless transmission using coherent terahertz wave with phase stabilization

“…Photonics-based generation of the THz wave in the coherent wireless link is a key technology for future optical/wireless seamless networks. There are two candidates for photonics-based THz wave generation: free-running laser-based approach [5] and optical frequency comb (OFC)-based approach [6,7]. In the free-running laser-based approach (see Fig.…”

“…1 (b)), the frequency-detuned optical signals for THz wave generation were extracted from the OFC with an optical arrayed-waveguide grating (AWG) filter and then coupled with [6]. One of the effective ways to reduce the phase fluctuation is to integrate the AWG filter and the OC on a planar lightwave circuit (PLC) substrate in order to make the optical path length difference insensitive to ambient temperature and other external noise [7].…”

“…One of the effective ways to reduce the phase fluctuation is to integrate the AWG filter and the OC on a planar lightwave circuit (PLC) substrate in order to make the optical path length difference insensitive to ambient temperature and other external noise [7]. At this moment, however, it is not easy and cost-effective to integrate active devices such as optical modulators on PLCs to construct such systems as used in [6].…”