Sebastian Rodriguez

Outdoor

This letter proposes a W-band hybrid photonic wireless link based on a commercial small form-factor pluggable (SFP+) module and experimentally demonstrates its performance. Using a free running laser as local oscillator and heterodyne photonic upconversion, good frequency stability is achieved. Outdoor wireless transmission over 225 m with a bit error rate below 10-6 is demonstrated, and the maximum reach of the system with typical RF components is calculated, finding wireless distances above 2 km to be feasible. Being based on a commercial SFP+, the proposed hybrid photonic wireless link offers seamless integration with existing distribution networks and passive optical networks, and thus paves the way for future mobile frontand backhaul architectures.

W

In this paper a new type of radio access unit is proposed and demonstrated. This unit is composed only of the reduced amount of components (compared to conventional unit designs) to optically generate wireless signals on the W-band (75-110GHz) in combination with a switching system. The proposed system not only achieves BER values below the FEC limit, but gives an extra level of flexibility to the network by easing the redirection of the signal to different antennas.

-Band Hybrid Photonic Wireless Link Based on an Optical SFP+ Module

We report on optically controlled antennas and photonic downconversion for mm-wave wireless communication applications. Experimental results demonstrate a transmission of 1.25 Gb/s using 28 and 38GHz frequency bands.

Reconfigurable radio access unit to dynamically distribute W-band signals in 5G wireless access networks

Nowadays several research projects are under progress to manage a soft migration toward the 5th generation networks. Radio over Ethernet (RoE) is one of recent topics that try to have a cost efficient and independent front-haul network. In this paper, we discuss the requirements of the 5G networks and analyze the conditions for the implementation of a RoE protocol. For this purpose we digitalize radio frames that are taken from BBU or RRH and create RoE basic frames considering all the requirements of protocol. We then encapsulate RoE basic frames into an Ethernet packet and finally experimentally evaluate this Ethernet packet as a case of study for RoE applications. The packet is transmitted through different fiber spans, measuring the BER and latency on each case. The system achieves BER values below the FEC limit and a manageable latency. These results serve as a guideline and proof of concept for applications on RoE, showing the viability of its implementation as part of the next generation of front-haul networks.

Photonic downconversion and optically controlled reconfigurable antennas in mm-waves wireless networks

This paper reports on an ultra-wideband (UWB) Schottky diode based balanced envelope detector for the L-, S-, C- and X- bands. The proposed circuit consists of a balun that splits the input signal into two 180° out of phase signals, a balanced detector, that demodulates the two signals, a low pass filter that rejects the second harmonic spurious from the Schottky diode and a bias tee that selects the optimum rectification point. The manufactured prototype is able to demodulate error free a 4 Gbps amplitude shift keying (ASK) signal at 4 GHz carrier frequency, leading to a record bitrate to frequency carrier ratio (Δb) of 100%. Besides this, the detector achieves error free demodulation for carrier frequencies between 4 and 8 GHz, while keeping the bitrate at 4 Gbps.

Latency and bit-error-rate evaluation for radio-over-ethernet in optical fiber front-haul networks

The increasing demand for bandwidth in datacenter interconnect links is currently driving a transition towards four level pulse-amplitude modulation (PAM-4) as the de facto modulation format. Nevertheless, other schemes with even higher spectral efficiency will be required in the future given the challenges of increasing baud rate or number of channels. As enabling technology, we propose and demonstrate a coherent link concept inspired from passive optical networks (PON) where carrier delivery and remote modulation are used to achieve single wavelength transmission of polarization multiplexing quadrature phase shift keying (PM-QPSK) at 112 Gb/s in channels of 5 and 10 km single mode fiber (SMF). By using a single laser for modulation and local oscillator the required complexity of digital signal processing is reduced in comparison to traditional digital coherent links.

Ultra-wideband balanced schottky envelope detector for data communication with high bitrate to carrier frequency ratio

Abstract. A spatial circuit switching system based on a beam steering application for W-band wireless links is proposed and experimentally demonstrated. The system enables two simultaneous transmissions of a 2.5  Gbit/s data signal over a carrier of 81 GHz, while allowing the receiver to dynamically switch between them. The performance of the system is tested with the real-time measurements of the BER, achieving values below the FEC limit for 7% of overhead and serving to prove the viability of wireless spatial circuit switching in the next generation of wireless access networks.

Short range inter-datacenter transmission with carrier delivery and remote modulation for 112 Gb/s PM-QPSK signals

Ubiquitous broadband Internet access is one of the major goals of the next generation of wireless communications. However, there are still some locations where this is difficult to achieve. This is the case on moving vehicles and, particularly, on trains. Among the possible solutions to this problem, RoF (Radio-over-Fiber) architectures have been proposed as low-latency, cost-effective candidates. Two elements are introduced to extend the RoF approach. First, the carrier frequency is raised into the W-band (75–110 GHz) to increase the available capacity. Second, a mechanical beam-steering solution based on a Stewart platform is adopted for the transmitter antenna to allow it to follow a moving receiver along a known path, thereby enhancing the coverage area. The performance of a system transmitting a 2.5 Gbit/s non-return-to-zero signal generated by photonic up-conversion over a wireless link is evaluated in terms of real-time BER (Bit Error Rate) measurements. The receiver is situated in different positions, and the orientation of the transmitter is changed accordingly. Values below the forward error correction limit for 7% overhead are obtained over a range of 60 cm around a center point situated 2 m away from the transmitter.

Real-time 2.5 Gbit/s spatial circuit switching on W-band wireless links

This paper proposes and demonstrates an RFID-over-Fiber wireless track and trace system using active RFID tags and operating over distances up to 30 km of optical fiber and 35 meters of wireless readability.

Beam steering application for W-band data links with moving targets in 5G wireless networks

This paper demonstrates experimentally the distribution of radio-over-fiber (RoF) signals using orbital angular momentum (OAM) of light over standard OM4 multimode fiber (MMF) at 850 nm wavelength. Five independent OAM modes are used to convey RoF signals in the microwave regime showing robust performance and therefore opening new prospects for enhancing the capacity of MMF based RoF Links.