Performance analysis of long band passive optical network using amplifier spontaneous noise and fiber Bragg gratings

Long band (L-Band) passive optical networks (PONs) are attracting a lot of attention these days, thanks to rising capacity demands. Because of PONs requesting more and more channels, fault detection/monitoring is critical. Fault detection in the conventional band (C-Band) employing reflecting Fiber Bragg Gratings (FBGs) and a probe signal integrating an additional amplified spontaneous noise (ASEN) source has been frequently demonstrated. However, interference occurs when ASEN and transmitter signals are in the same wavelength band, and adding additional ASEN sources to the network raises the overall cost. So, in L-Band PONs, a cost-effective, low-complexity fault detection/monitoring system is required. Therefore, in this work, a fault detection/monitoring system for L-Band PON using C-Band ASEN from inline erbium doped fiber amplifier (EDFA) and dual purpose FBG, i.e. (1) ASEN reflection for fault monitoring and (2) dispersion compensation is proposed. A 4 × 10 Gbps L-Band PON is investigated over 40 km feeder fiber (FF) and 1 km drop fibers (DFs) that serve 32 optical network units (ONUs)/different input powers, dispersion values, and laser linewidths in terms of reflective power of FBGs, eye opening factor, and bit error rate (BER), respectively.

Deducing of Optical and Electronic Domains Based Distortions in Radio over Fiber Network

Managing the users multimedia and long-range based demands, the radio over fiber (RoF) mechanism has been introduced recently. RoF mingles the optical and radio communication frameworks to increase mobility and offer high capacity communication networks (CNs). In this paper, a full-duplex RoF-based CN is investigated for the next-generation passive optical network (PON), utilizing wavelength division multiplexing (WDM) technology. The desolations on account of optical and electronic domains (OEDs) are addressed, using dispersion compensation fiber (DCF) and optical and electrical filters, including modulation scheme. The analytical and simulation models are analyzed in terms of phase error (PE), radio frequency (RF), fiber length and input and received powers. The performance of the proposed model is successfully evaluated for 50 km range, −40 to −18 dBm received power, −20 to 0 dBm input power, where below 10−6 bit error rate (BER) is recorded. Thus, this signifies that the presented model exhibits smooth execution against OEDs impairments.

Optimization and Performance Analysis of Dispersion Compensation in RZ and NRZ Systems with Transmission Rates of 10 Gbps and 40 Gbps / Otimização e Análise da Compensação de Dispersão em Sistemas de RZ e NRZ com Taxas de Transmissão de 10 Gbps e 40 Gbps

Neste trabalho, investigamos um método de compensação de dispersão para as taxas de transmissão de 10 Gbps e 40 Gbps com formatos de modulação retorno ao zero (return to zero - RZ) e não retorno ao zero (non-return to zero - NRZ) usando fibra monomodo (single mode-fiber - SMF) e fibra compensadora de dispersão (dispersion compensating fiber - DCF). A influência da dispersão do compensador DCF com o aumento da potência do laser CW foi estudada, afim de se avaliar o desempenho dos sistemas de comunicação por fibra óptica aqui propostos. Os resultados da simulação foram validados através do formato do pulso, do espectro óptico e do diagrama de olho para a análise do fator Q e da taxa de erro de bit (bit error rate – BER).

CHROMATIC DISPERSION COMPENSATION IN EXISTING FIBER OPTIC TELECOMMUNICATION LINES WITH THE GROWING BIT RATES NEEDS OF DWDM SYSTEM

The article presents an analysis of the methods of chromatic dispersion compensation in the existing, already built fiber optic telecommunications lines, based on ITU G.652 A and B fibers with the constantly growing demand for bit rates in DWDM systems. Due to the enormous investment costs, it is impossible to replace the cables used with NZDSF, hence the chapter analyzes methods of improving the bandwidth without replacing all cables. Typical models of the optimization of chromatic dispersion in the existing lines are presented.

Photonic Remote Microwave Frequency Measurement With a Tunable Measurement Range Based on Dispersion Compensation Technology

In this paper, a novel and efficient photonic-assisted remote frequency measurement (RFM) system with a significantly simplified structure and flexible operation range is proposed. By simply changing the dispersion coefficient or length of the dispersion medium in the central station (CS), the microwave frequency measurement range in the remote antenna unit (RAU) can be tuned. In this system, the RAU and the CS is separated to ensure the concealment and safety of the signal processing unit. The measurement range of the RFM system can be tuned easily during the measurement process without system reconstruction, and different RAUs located at different places can be controlled to work at the same measurement range. The simulation results show that a frequency measurement over the high frequency range (>18 GHz) can be achieved with a measurement error better than ±0.2 GHz. Noteworthy, the impact of the non-ideal factors such as bias drift, intensity noise, phase noise, the equivalent deviation of the polarization beam splitter (PBS), and the dispersion value of the single mode fiber (SMF) is also discussed. It has been proved that they have little influence on the system performance over the high frequency range.

Optical Channel Selection Avoiding DIPP in DSB-RFoF Fronthaul Interface

The paper presents a method of selecting an optical channel for transporting the double-sideband radio-frequency-over-fiber (DSB-RFoF) radio signal over the optical fronthaul path, avoiding the dispersion-induced power penalty (DIPP) phenomenon. The presented method complements the possibilities of a short-range optical network working in the flexible dense wavelength division multiplexing (DWDM) format, where chromatic dispersion compensation is not applied. As part of the study, calculations were made that indicate the limitations of the proposed method and allow for the development of an algorithm for effective optical channel selection in the presence of the DIPP phenomenon experienced in the optical link working in the intensity modulation–direct detection (IM-DD) technique. Calculations were made for three types of single-mode optical fibers and for selected microwave radio carriers that are used in current systems or will be used in next-generation wireless communication systems. In order to verify the calculations and theoretical considerations, a computer simulation was performed for two types of optical fibers and for two selected radio carriers. In the modulated radio signal, the cyclic-prefix orthogonal frequency division multiplexing (CP-OFDM) format and the 5G numerology were used.