Xianbin Yu | Zhejiang University (original) (raw)

Papers by Xianbin Yu

Research paper thumbnail of Impact of group delay ripples of chirped fiber grating on optical beamforming networks

Optics Express, 2008

The impact of group delay ripples of chirped fiber gratings (CFG) on the performance of optical b... more The impact of group delay ripples of chirped fiber gratings (CFG) on the performance of optical beamforming networks (OBFN) is investigated. The paper theoretically analyzes the quantified relations among the amplitude and period of CFG, the optical angle frequency interval at the inter-element arrays and the beampointing shift. The wavelength instability of the optical source is also investigated. This instability-induced phase jitter of RF signal has been verified experimentally. The theoretical models are proposed to analyze the performance of CFG-based OBFN systems.

Research paper thumbnail of Optical Beamforming Networks Based on Broadband Optical Source and Chirped Fiber Grating

IEEE Photonics Technology Letters, 2008

We propose a photonic beamforming network scheme based on a broadband optical source and chirped ... more We propose a photonic beamforming network scheme based on a broadband optical source and chirped fiber grating. The principle and feasibility are proved by both theoretical analysis and experiments. In 1-to 18-GHz microwave band, experimental results show a good delay time consistency and the ratio of signal-to-noise met the practical application demands. The time consistency errors are smaller than 1 ps in 9.25-to 10.25-GHz band. Especially, the effects of group delay ripple are effectively mitigated compared with the tunable laser source scheme, which agree well with the theoretical results.

Research paper thumbnail of Polarization state rotation filter for optical generation of continuously tunable millimeter-wave signal employing an external intensity modulator

Optical Fiber Technology, 2007

ABSTRACT

Research paper thumbnail of High carrier suppression double sideband modulation using polarization state rotation filter and optical external modulator

Optics Communications, 2006

ABSTRACT

Research paper thumbnail of Experimental performance comparison of 60 GHz DCM OFDM and impulse BPSK ultra-wideband with combined optical fibre and wireless transmission

We present an experimental performance comparison of 1.44Gbps dual-carrier modulation OFDM and BP... more We present an experimental performance comparison of 1.44Gbps dual-carrier modulation OFDM and BPSK impulse-radio ultra-wideband in the 60GHz band with combined fibre, up to 40km, and 5m wireless transmission. Impulse-radio exhibits better dispersion tolerance requiring lower optical power.

Research paper thumbnail of A Comparison of Electrical and Photonic Pulse Generation for IR-UWB on Fiber Links

IEEE Photonics Technology Letters, 2010

We present and compare experimental results for electrical and photonic generation of 2-Gb/s puls... more We present and compare experimental results for electrical and photonic generation of 2-Gb/s pulses for impulse radio ultra-wideband on fiber transmission systems based on direct current modulation of a semiconductor laser diode and external optical injection of a semiconductor laser diode, respectively. We assess the performance of the two generation approaches in terms of bit-error rate after propagation over 20 km of optical fiber followed by wireless transmission.

Research paper thumbnail of Compact wireless access nodes for WDM bidirectional radio-over-fiber system based on RSOA

We demonstrate a RSOA based WDM radio-over-fiber, bidirectional system for wireless access networ... more We demonstrate a RSOA based WDM radio-over-fiber, bidirectional system for wireless access networks. The multi-functionalities of a RSOA, such as colorless operation, re-modulation and envelope detection, make wireless access nodes more compact.

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

IEEE Journal on Selected Areas in Communications, 2011

The performance of radio-over-fiber optical transmission employing vertical-cavity surface-emitti... more The performance of radio-over-fiber optical transmission employing vertical-cavity surface-emitting lasers (VC-SELs), 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.

Research paper thumbnail of Photonic generation of UWB monocycle pulses using a cascaded semiconductor optical amplifier and electroabsorption modulator

Photonic generation of ultrawideband monocycle pulses is experimentally demonstrated by using a c... more Photonic generation of ultrawideband monocycle pulses is experimentally demonstrated by using a cascaded semiconductor optical amplifier and electroabsorption modulator. The polarity and the shape of the ultrawideband monocycle pulses can be electrically controlled and optimized.

Research paper thumbnail of Photonic microwave transversal filter employing a fiber-Bragg-grating-based multiple resonator

Microwave and Optical Technology Letters, 2005

In this paper, we present a photonic microwave transversal filter with a multiple-fiber resonator... more In this paper, we present a photonic microwave transversal filter with a multiple-fiber resonator formed by cascaded fiber Bragg gratings. The filter-free spectral range is extended via the Vernier effect, which can increase the filter rejection bandwidth and suppress the unwanted periodic passbands. The experiment is demonstrated to confirm the feasibility of the proposed scheme. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 44: 369–371, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20637

Research paper thumbnail of A novel incoherent scheme for Photonic Generation of Biphase Modulated UWB Signals

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

IEEE Photonics Technology Letters, 2009

In this letter, an all-optical incoherent scheme for generation of binary phase-coded ultra-wideb... more 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 ) 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.

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

IEEE Photonics Technology Letters, 2008

We propose and demonstrate a bidirectional radio-over-fiber (RoF) system based on a reflective se... more 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.

Research paper thumbnail of Optically envelope detected QAM and QPSK RF modulated signals in hybrid wireless-fiber systems

Microwave and Optical Technology Letters, 2009

We experimentally demonstrate optical envelope detection of 40 Mbaud 16-QAM and QPSK RF modulated... more We experimentally demonstrate optical envelope detection of 40 Mbaud 16-QAM and QPSK RF modulated signals. The proposed system employs an electro-absorption modulator performing the function of an optical halfwave rectifier. In this experiment, the QAM and QPSK signals are frequency down converted from a 1.6 GHz carrier frequency to an IF at 500 MHz, requiring no high frequency local oscillator and mixer at the remote base station. This result proves the feasibility of optical envelope detection for complex modulation formats of RF signals for hybrid wireless-fiber transmission links. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 864–866, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24182

Research paper thumbnail of Combined transmission of baseband NRZ-DQPSK and phase modulated radio-over-fibre

21.4 Gbit/s baseband DQPSK and 1.25 Gbit/s phase modulated RoF was transmitted over 80 km SSMF us... more 21.4 Gbit/s baseband DQPSK and 1.25 Gbit/s phase modulated RoF was transmitted over 80 km SSMF using polarization multiplexing.

Research paper thumbnail of 3.125 Gb/s Impulse Radio Ultra-Wideband Photonic Generation and Distribution Over a 50 km Fiber With Wireless Transmission

IEEE Microwave and Wireless Components Letters, 2010

A 3.125 Gb/s photonic impulse radio ultra-wideband signal is created using the incoherent optical... more A 3.125 Gb/s photonic impulse radio ultra-wideband signal is created using the incoherent optical field summation resulting from the cross gain modulation of an uncooled distributed feedback laser injected with an external cavity laser. After 50 km of fiber and wireless transmission over 2.9-3.3-m, successful detection using a digital signal processing receiver is achieved.

Research paper thumbnail of Digital Coherent Receiver for Phase-Modulated Radio-Over-Fiber Optical Links

IEEE Photonics Technology Letters, 2009

A novel digital signal processing-based coherent receiver for phase-modulated radio-over-fiber (R... more 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 3 50 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.

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

IEEE Photonics Journal, 2012

In this paper, we demonstrate a photonic up-converted 25 Gbit/s fiber-wireless quadrature phase s... more 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 downconversion 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 Â 10 À3 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).

Research paper thumbnail of Bidirectional 3.125 Gbps downstream / 2 Gbps upstream impulse radio ultrawide-band (UWB) over combined fiber and wireless link

ABSTRACT We demonstrate bidirectional fiber and wireless transmission of impulse radio ultra-wide... more ABSTRACT We demonstrate bidirectional fiber and wireless transmission of impulse radio ultra-wideband at 3.125 Gbps downstream and 2 Gbps upstream. After transmission over 50 km fiber and 1.85 m wireless link both signals are recovered without errors.

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

Optics Express, 2009

A photonic ultra-wideband (UWB) pulse generator based on relaxation oscillations of a semiconduct... more 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.

Research paper thumbnail of Impact of group delay ripples of chirped fiber grating on optical beamforming networks

Optics Express, 2008

The impact of group delay ripples of chirped fiber gratings (CFG) on the performance of optical b... more The impact of group delay ripples of chirped fiber gratings (CFG) on the performance of optical beamforming networks (OBFN) is investigated. The paper theoretically analyzes the quantified relations among the amplitude and period of CFG, the optical angle frequency interval at the inter-element arrays and the beampointing shift. The wavelength instability of the optical source is also investigated. This instability-induced phase jitter of RF signal has been verified experimentally. The theoretical models are proposed to analyze the performance of CFG-based OBFN systems.

Research paper thumbnail of Optical Beamforming Networks Based on Broadband Optical Source and Chirped Fiber Grating

IEEE Photonics Technology Letters, 2008

We propose a photonic beamforming network scheme based on a broadband optical source and chirped ... more We propose a photonic beamforming network scheme based on a broadband optical source and chirped fiber grating. The principle and feasibility are proved by both theoretical analysis and experiments. In 1-to 18-GHz microwave band, experimental results show a good delay time consistency and the ratio of signal-to-noise met the practical application demands. The time consistency errors are smaller than 1 ps in 9.25-to 10.25-GHz band. Especially, the effects of group delay ripple are effectively mitigated compared with the tunable laser source scheme, which agree well with the theoretical results.

Research paper thumbnail of Polarization state rotation filter for optical generation of continuously tunable millimeter-wave signal employing an external intensity modulator

Optical Fiber Technology, 2007

ABSTRACT

Research paper thumbnail of High carrier suppression double sideband modulation using polarization state rotation filter and optical external modulator

Optics Communications, 2006

ABSTRACT

Research paper thumbnail of Experimental performance comparison of 60 GHz DCM OFDM and impulse BPSK ultra-wideband with combined optical fibre and wireless transmission

We present an experimental performance comparison of 1.44Gbps dual-carrier modulation OFDM and BP... more We present an experimental performance comparison of 1.44Gbps dual-carrier modulation OFDM and BPSK impulse-radio ultra-wideband in the 60GHz band with combined fibre, up to 40km, and 5m wireless transmission. Impulse-radio exhibits better dispersion tolerance requiring lower optical power.

Research paper thumbnail of A Comparison of Electrical and Photonic Pulse Generation for IR-UWB on Fiber Links

IEEE Photonics Technology Letters, 2010

We present and compare experimental results for electrical and photonic generation of 2-Gb/s puls... more We present and compare experimental results for electrical and photonic generation of 2-Gb/s pulses for impulse radio ultra-wideband on fiber transmission systems based on direct current modulation of a semiconductor laser diode and external optical injection of a semiconductor laser diode, respectively. We assess the performance of the two generation approaches in terms of bit-error rate after propagation over 20 km of optical fiber followed by wireless transmission.

Research paper thumbnail of Compact wireless access nodes for WDM bidirectional radio-over-fiber system based on RSOA

We demonstrate a RSOA based WDM radio-over-fiber, bidirectional system for wireless access networ... more We demonstrate a RSOA based WDM radio-over-fiber, bidirectional system for wireless access networks. The multi-functionalities of a RSOA, such as colorless operation, re-modulation and envelope detection, make wireless access nodes more compact.

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

IEEE Journal on Selected Areas in Communications, 2011

The performance of radio-over-fiber optical transmission employing vertical-cavity surface-emitti... more The performance of radio-over-fiber optical transmission employing vertical-cavity surface-emitting lasers (VC-SELs), 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.

Research paper thumbnail of Photonic generation of UWB monocycle pulses using a cascaded semiconductor optical amplifier and electroabsorption modulator

Photonic generation of ultrawideband monocycle pulses is experimentally demonstrated by using a c... more Photonic generation of ultrawideband monocycle pulses is experimentally demonstrated by using a cascaded semiconductor optical amplifier and electroabsorption modulator. The polarity and the shape of the ultrawideband monocycle pulses can be electrically controlled and optimized.

Research paper thumbnail of Photonic microwave transversal filter employing a fiber-Bragg-grating-based multiple resonator

Microwave and Optical Technology Letters, 2005

In this paper, we present a photonic microwave transversal filter with a multiple-fiber resonator... more In this paper, we present a photonic microwave transversal filter with a multiple-fiber resonator formed by cascaded fiber Bragg gratings. The filter-free spectral range is extended via the Vernier effect, which can increase the filter rejection bandwidth and suppress the unwanted periodic passbands. The experiment is demonstrated to confirm the feasibility of the proposed scheme. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 44: 369–371, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20637

Research paper thumbnail of A novel incoherent scheme for Photonic Generation of Biphase Modulated UWB Signals

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

IEEE Photonics Technology Letters, 2009

In this letter, an all-optical incoherent scheme for generation of binary phase-coded ultra-wideb... more 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 ) 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.

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

IEEE Photonics Technology Letters, 2008

We propose and demonstrate a bidirectional radio-over-fiber (RoF) system based on a reflective se... more 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.

Research paper thumbnail of Optically envelope detected QAM and QPSK RF modulated signals in hybrid wireless-fiber systems

Microwave and Optical Technology Letters, 2009

We experimentally demonstrate optical envelope detection of 40 Mbaud 16-QAM and QPSK RF modulated... more We experimentally demonstrate optical envelope detection of 40 Mbaud 16-QAM and QPSK RF modulated signals. The proposed system employs an electro-absorption modulator performing the function of an optical halfwave rectifier. In this experiment, the QAM and QPSK signals are frequency down converted from a 1.6 GHz carrier frequency to an IF at 500 MHz, requiring no high frequency local oscillator and mixer at the remote base station. This result proves the feasibility of optical envelope detection for complex modulation formats of RF signals for hybrid wireless-fiber transmission links. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 864–866, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24182

Research paper thumbnail of Combined transmission of baseband NRZ-DQPSK and phase modulated radio-over-fibre

21.4 Gbit/s baseband DQPSK and 1.25 Gbit/s phase modulated RoF was transmitted over 80 km SSMF us... more 21.4 Gbit/s baseband DQPSK and 1.25 Gbit/s phase modulated RoF was transmitted over 80 km SSMF using polarization multiplexing.

Research paper thumbnail of 3.125 Gb/s Impulse Radio Ultra-Wideband Photonic Generation and Distribution Over a 50 km Fiber With Wireless Transmission

IEEE Microwave and Wireless Components Letters, 2010

A 3.125 Gb/s photonic impulse radio ultra-wideband signal is created using the incoherent optical... more A 3.125 Gb/s photonic impulse radio ultra-wideband signal is created using the incoherent optical field summation resulting from the cross gain modulation of an uncooled distributed feedback laser injected with an external cavity laser. After 50 km of fiber and wireless transmission over 2.9-3.3-m, successful detection using a digital signal processing receiver is achieved.

Research paper thumbnail of Digital Coherent Receiver for Phase-Modulated Radio-Over-Fiber Optical Links

IEEE Photonics Technology Letters, 2009

A novel digital signal processing-based coherent receiver for phase-modulated radio-over-fiber (R... more 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 3 50 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.

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

IEEE Photonics Journal, 2012

In this paper, we demonstrate a photonic up-converted 25 Gbit/s fiber-wireless quadrature phase s... more 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 downconversion 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 Â 10 À3 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).

Research paper thumbnail of Bidirectional 3.125 Gbps downstream / 2 Gbps upstream impulse radio ultrawide-band (UWB) over combined fiber and wireless link

ABSTRACT We demonstrate bidirectional fiber and wireless transmission of impulse radio ultra-wide... more ABSTRACT We demonstrate bidirectional fiber and wireless transmission of impulse radio ultra-wideband at 3.125 Gbps downstream and 2 Gbps upstream. After transmission over 50 km fiber and 1.85 m wireless link both signals are recovered without errors.

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

Optics Express, 2009

A photonic ultra-wideband (UWB) pulse generator based on relaxation oscillations of a semiconduct... more 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.