\n Next generation wireless networks are the need of the hour with reliable, high bandwidth, low Bit Error Rate (BER), high Signal to Noise Ratio (SNR), large network capacity, etc. for a paradigm shift to all optical networks from the prevailing conventional electro optic network due to the various benefits of optical links such as enormous bandwidth and extremely low losses. This paper presents a primitive overview of the foregoing technologies and then move on to encapsulating the contemporary techniques to enhance the system performance. For this, preceding limitation and their respective improvement measures from literature of fiber communication and its integration with the next generation networks mainly based upon Radio over Fiber (RoF), Fiber to the Home (FTTH) and Free Space Optics (FSO) are discussed. The advancement in the domain of optical wireless communication utilizing various methodologies is summarized. Finally, we conclude by incorporating various cost reduction methodologies developed which may further be explored to make next generation networks more promising.

Next generation optical wireless communication: a comprehensive review

This paper presents analytical analysis for a linearization method of a microwave photonic (MWP) link based on dual-drive dual-parallel Mach–Zehnder Modulator. Electric phase shifters are utilized to suppress intermodulation distortion terms and to further increase linearity of the link. A simulation model is designed to evaluate spurious free dynamic range (SFDR) against third order intermodulation distortion as it is a key performance measurement parameter of MWP link. A suppression of 68 dB is found in intermodulation terms and SFDR enhances by 16 dB which ensures the improvement in performance of link against intermodulation terms.

Linearization of Photonic Link Based on Phase-Controlled Dual Drive Dual-Parallel Mach–Zehnder Modulator

The demands of Academia, Industries, data-hungry applications and user-defined services conceptualizing the next generation networks such as fifth Generation (5G) or sixth Generation (6G) Wireless Networks. The major challenges for next generation networks are energy efficient communication and green environment with potential health issues. The important substitute for green radio communication is Radio over Fiber System (RoF) System. The high quality, high security, large capacity, optimized energy consumption, low latency, economic solution for long distance etc., are assured by RoF system. The 120° phase shift based high performance RoF system is utilized against intermodulation (IM3) terms. In this paper, the performance of 120° phase shift based RoF system with erbium doped fiber amplifier (EDFA) is analysed, modelled and simulated. The impact of noise and distortion environment w.r.t. input RF signal power are investigated. Further, the spurious free dynamic range (SFDR) of proposed system with EDFA is also evaluated while considering fundamental and IM3 power variations. The SFDR is found as 149.5 and 122.22 dB/Hz2/3 for proposed system with and without EDFA, respectively. This dynamic range calculation of proposed system defines the need of dispersion compensation fiber (DCF) for proposed system with EDFA for nonlinearities and challenging applications.

Optimization of High Performance Generation Method Based RoF System by Employing Optic Amplifier Link

Abstract A scheme to suppress nonlinear intermodulation distortion in microwave photonic (MWP) link is proposed by using polarizers to compensate inherent non-linear behavior of dual-electrode Mach-Zehnder modulator (DE-MZM). Insertion losses and extinction ratio have also been considered. Simulation results depict that spurious free dynamic range (SFDR) of proposed link reaches to 130.743 dB.Hz2/3. A suppression of 41 dB in third order intermodulation distortions and an improvement of 15.3 dB is reported when compared with the conventional link. In addition, an electrical spectrum at different polarization angles is extracted and 79∘79^\\circ is found to be optimum value of polarization angle.

Mitigating the Effects of Non-Linear Distortion Using Polarizers in Microwave Photonic Link

This paper provides an overview of linearization of two different microwave photonic links based on phase modulator and dual-electrode Mach–Zehnder modulator. It takes into account the problem of intermodulation distortion which can severely degrade the performance of the system. Spurious free dynamic range has been analyzed through numerical and simulation for both the modulator links which are linearized using mixed polarization. Improvements of 7.3 dB and 15.1 dB are found in SFDR using polarizers in phase and Mach–Zehnder modulator, respectively.

Comparative analysis of microwave photonic links based on different modulators using polarizers

In this paper, an analytical model is represented to analyze and improve the performance of radio over fiber (RoF) links against nonlinear distortion. RoF transmission link comprised of a phase modulator, polarizer and optical filter is considered. By controlling angles of polarization, the signals are fed to the modulator. Polarizer helps to suppress intermodulation distortion along the considered link. Performance is found in terms of spurious-free dynamic range (SFDR). Results show an improvement of 7.5-dB in SFDR for a polarized link in comparison with the conventional link.

RoF system based on phase modulator-employing polarization for linearization

Radio-over-Fiber (RoF) links has become a promising technique to deliver effective communication as it offers broad bandwidth and low losses. To enhance the link performance, numerous techniques have been reported. This article reviews techniques used to linearize RoF links i.e. optical and electrical linearization. A comparison table has been drawn considering bandwidth, non-linearity, losses, link complexity & cost. It is found that optical linearization is the most suitable technique for the linearization of link. Hence, this technique is further discussed and its different types have been explored.

Sarika Singh

Papers

RoF system based on phase modulator-employing polarization for linearization

Linearization of Photonic Link Based on Phase-Controlled Dual Drive Dual-Parallel Mach–Zehnder Modulator

Mitigating the Effects of Non-Linear Distortion Using Polarizers in Microwave Photonic Link

Comparative analysis of microwave photonic links based on different modulators using polarizers

A Study & Review of Various Optical Linearization Techniques for Next Generation RoF Networks