Xianbin Yu

100 Gbit/s hybrid optical fiber-wireless link in the W-band (75–110 GHz)

We experimentally demonstrate an 100 Gbit/s hybrid optical fiber-wireless link by employing photonic heterodyning up-conversion of optical 12.5 Gbaud polarization multiplexed 16-QAM baseband signal with two free running lasers. Bit-error-rate performance below the FEC limit is successfully achieved for air transmission distances up to 120 cm.

Digital Coherent Receiver for Phase-Modulated Radio-Over-Fiber Optical Links

A novel digital signal processing-based coherent receiver for phase-modulated radio-over-fiber (RoF) optical links is presented and demonstrated experimentally. Error-free demodulation of 50-Mbaud binary phase-shift keying (BPSK) and quadrature phase-shift keying data signal modulated on a 5-GHz radio-frequency (RF) carrier is experimentally demonstrated using the proposed digital coherent receiver. Additionally, a wavelength- division-multiplexing (WDM) phase-modulated RoF optical link is experimentally demonstrated. A 3times50 Mb/s WDM transmission of a BPSK modulated 5-GHz RF carrier is achieved over 25 km for the WDM channel spacing of 12.5 and 25 GHz, respectively.

Distribution of photonically generated 5 Gbits/s impulse radio ultrawideband signals over fiber.

We propose an approach to generate ultrawideband (UWB) pulses with tunable high-speed modulation based on pulse compression. Flexible generation of up to a record 5 Gbits/s on-off keying impulse radio UWB signals are successfully demonstrated as well. We also investigate 5 Gbits/s on-off keying bit-error-rate (BER) performance after 40 km single mode fiber transmission by employing a digital signal processing receiver, and the BER below forward error correction limit is achieved.

25 Gbit/s QPSK Hybrid Fiber-Wireless Transmission in the W-Band (75–110 GHz) With Remote Antenna Unit for In-Building Wireless Networks

In this paper, we demonstrate a photonic up-converted 25 Gbit/s fiber-wireless quadrature phase shift-keying (QPSK) data transmission link at the W-band (75-110 GHz). By launching two free-running lasers spaced at 87.5 GHz into a standard single-mode fiber (SSMF) at the central office, a W-band radio-over-fiber (RoF) signal is generated and distributed to the remote antenna unit (RAU). One laser carries 12.5 Gbaud optical baseband QPSK data, and the other acts as a carrier frequency generating laser. The two signals are heterodyne mixed at a photodetector in the RAU, and the baseband QPSK signal is transparently up-converted to the W-band. After the wireless transmission, the received signal is first down-converted to an intermediate frequency (IF) at 13.5 GHz at an electrical balanced mixer before being sampled and converted to the digital domain. A digital-signal-processing (DSP)-based receiver is employed for offline digital down-conversion and signal demodulation. We successfully demonstrate a 25 Gbit/s QPSK wireless data transmission link over a 22.8 km SSMF plus up to 2.13 m air distance with a bit-error-rate performance below the 2 × 10-3 forward error correction (FEC) limit. The proposed system may have the potential for the integration of the in-building wireless networks with the fiber access networks, e.g., fiber-to-the-building (FTTB).

Converged Wireline and Wireless Access Over a 78-km Deployed Fiber Long-Reach WDM PON

In this letter, we demonstrate a 78.8-km wavelength-division-multiplexing passive optical network supporting converged transport of 21.4-Gb/s nonreturn-to-zero differential quadrature phase-shift keying, optical phase-modulated 5-GHz radio-over-fiber, fiber and air transmission of 3.125-Gb/s pulse ultrawideband, and 256-quadratic-amplitude modulation wireless interoperability for microwave access.

A photonic ultra-wideband pulse generator based on relaxation oscillations of a semiconductor laser

A photonic ultra-wideband (UWB) pulse generator based on relaxation oscillations of a semiconductor laser is proposed and experimentally demonstrated. We numerically simulate the modulation response of a direct modulation laser (DML) and show that due to the relaxation oscillations of the laser, the generated signals with complex shape in time domain match the Federal Communications Commission (FCC) mask in the frequency domain. Experimental results using a DML agree well with simulation predictions. Furthermore, we also experimentally demonstrate the generation of FCC compliant UWB signals by externally injecting a distributed feedback (DFB) laser.

Fiber Wireless Transmission of 8.3-Gb/s/ch QPSK-OFDM Signals in 75–110-GHz Band

In this letter, we present a scalable high-speed W-band (75-110-GHz) fiber wireless communication system. By using an optical frequency comb generator, three-channel 8.3-Gb/s/ch optical orthogonal frequency-division-multiplexing (OOFDM) baseband signals in a 15-GHz bandwidth are seamlessly translated from the optical to the wireless domain. The W-band wireless carrier is generated from heterodyne mixing the OOFDM baseband signal with a free-running laser. A W-band electronic down-converter and a digital signal processing-based receiver are used. Three-channel QPSK-OFDM W-band wireless signals are transmitted over 0.5- and 2-m air distance with and without 22.8-km single-mode fiber, respectively, with achieved performance below the forward error correction limit.

Bidirectional Radio-Over-Fiber System With Phase-Modulation Downlink and RF Oscillator-Free Uplink Using a Reflective SOA

We propose and demonstrate a bidirectional radio-over-fiber (RoF) system based on a reflective semiconductor optical amplifier (RSOA). In this system, phase-modulated 5.25-GHz radio frequency (RF) carrying 850 Mb/s is used for the downstream signal. Optical envelope detection of 10-GHz RF carrying 850 Mb/s is achieved in an RSOA. Both signals share a single fiber link and the same light source by exploiting optical carrier remodulaiton. Moreover, there is no need to employ RF down-conversion technology for RoF uplink. This makes the proposed system simpler and more cost-effective. The experimental results indicate that after simultaneous transmission of downstream and upstream signals over 25-km fiber, the receiver sensitivities are -22 and -14.5 dBm, respectively.

Experimental Demonstration of All-Optical 781.25-Mb/s Binary Phase-Coded UWB Signal Generation and Transmission

In this letter, an all-optical incoherent scheme for generation of binary phase-coded ultra-wideband (UWB) impulse radio signals is proposed. The generated UWB pulses utilize relaxation oscillations of an optically injected distributed feedback laser that are binary phase encoded (0 and pi) and meet the requirements of Federal Communications Commission regulations. We experimentally demonstrated a 781.25-Mb/s UWB-over-fiber transmission system. A digital-signal-processing-based receiver is employed to calculate the bit-error rate. Our proposed system has potential application in future high-speed UWB impulse radio over optical fiber access networks.

Performance of a 60-GHz DCM-OFDM and BPSK-Impulse Ultra-Wideband System with Radio-Over-Fiber and Wireless Transmission Employing a Directly-Modulated VCSEL

The performance of radio-over-fiber optical transmission employing vertical-cavity surface-emitting lasers (VCSELs), and further wireless transmission, of the two major ultra-wideband (UWB) implementations is reported when operating in the 60-GHz radio band. Performance is evaluated at 1.44 Gbit/s bitrate. The two UWB implementations considered employ dual-carrier modulation orthogonal frequency-division multiplexing (DCM-OFDM) and binary phase-shift keying impulse radio (BPSK-IR) modulation respectively. Optical transmission distances up to 40 km in standard single-mode fiber and up to 500 m in bend-insensitive single-mode fiber with wireless transmission up to 5 m in both cases is demonstrated with no penalty. A simulation analysis has also been performed in order to investigate the operational limits. The analysis results are in excellent agreement with the experimental work and indicate good tolerance to chromatic dispersion due to the chirp characteristics of electro-optical conversion when a directly-modulated VCSEL is employed. The performance comparison indicates that BPSK-IR UWB exhibits better tolerance to optical transmission impairments requiring lower received optical power than its DCM-OFDM UWB counterpart when operating in the 60-GHz band.