300-GHz-band wireless communication using a low phase noise photonic source

Abstract

The implementation of advanced multi-level modulation schemes such as quadrature phase-shift keying (QPSK) in contrast to the conventional on–off keying is crucial to further boost the terahertz (THz) communications speed. Thereby, carrier phase noise reduction in the THz range is one of the key goals that need to be urgently achieved. In this paper, the photonic-based THz sources and the phase noise problem are briefly summarized. Then, a low phase-noise photonic source based on the stimulated Brillouin scattering (SBS) optical fiber cavity is first applied for a 300-GHz-band QPSK wireless communication link. The highest data rate at forward-error-correction limited condition was 15 Gbaud utilizing the SBS-based photonic source with a small transmit power of ~ −36 dBm. Its transmission characteristics are evaluated and compared with the conventional optical frequency comb generator (OFCG)-based source at 5 Gbaud. The proposed SBS-based photonic source has been proven to offer better performances than the OFCG-based source with respect to the phase noise, optical carrier to noise ratio, and bit error rate in communications.

Single-channel 240-Gbit/s sub-THz wireless communications using ultra-low phase noise receiver

“…As is already pointed out that the phase noise affects the BER characteristics of the communication systems [13][14][15][16][17], it could be concluded that the difference in the BER characteristics of Fig. 5 is related to the difference in the phase noise between the two LO signal sources.…”

“…In the multi-level signal modulation schemes, when the multi-level number increases, not only higher signal-tonoise ratio (SNR) but also reduction in the phase noise of radio frequency (RF) and local oscillator (LO) signals are required in the sub-THz communications systems [14][15][16]. Against this background, we proposed the use of a low-noise photonic sub-THz signal generator using a stimulated Brillouin scattering (SBS) light source for RF signals [17], and for both the RF and LO signals [18]. In the latter system, the maximum data rate was 80 Gbit/s with 16QAM at 300 GHz.…”

Single- Versus Multicarrier Terahertz-Band Communications: A Comparative Study

“…We first verify our assumption of Gaussian PHN for THz communications. We incorporate the PHN measurement results in [81] for a 300 GHz signal source, a PHN floor level of 𝐾 0 = −110 dBc/Hz, and 𝐾 2 = 10 ( 𝑓 cor = 1 MHz); we set 𝐵 = 10 GHz, which satisfies (18). We consider Tx PHN without loss of generality.…”

Single- versus Multi-Carrier Terahertz-Band Communications: A Comparative Study

“…We first verify our assumption of Gaussian PHN for THz communications. We incorporate the PHN measurement results in [67] for a 300 GHz signal source, a PHN floor level of 𝐾 0 = −110 dBc/Hz, and 𝐾 2 = 10 ( 𝑓 cor = 1 MHz); we set 𝐵 = 10 GHz, which satisfies (17). We consider Tx PHN without loss of generality.…”