A Study of various Trends and Enabling Technologies in Radio over Fiber (RoF) Systems

Sarup, Viyoma; Gupta, Amit

doi:10.1016/j.ijleo.2015.06.028

Cited by 23 publications

(4 citation statements)

References 21 publications

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“…During the past three decades, the telecommunication industry has faced an impressive growth not only in the number of subscribers worldwide, but also in the demand for higher-speed data transmissions [1]. To this end, orthogonal frequency division multiplexing (OFDM)-based radio-over-fiber (RoF) technology, combining the benefits of optical fiber and millimeter-wave wireless links, has been proven as the solution to support secure, cost-effective, and high-capacity vehicular/mobile/wireless access for the topic generation communication systems [2]. There are two types of receiver used in the implementation of RoF-OFDM systems: direct detection [3] and coherent detection [4].…”

Section: Introductionmentioning

confidence: 99%

“…The main contributions of the manuscript can be summarized as follows: (1) The ELM algorithms in the real and complex domains for phase noise estimation are introduced for the first time, by exploiting the pilots to achieve a real-time learning stage, as well as to maintain the spectral efficiency. (2) In terms of the bit error rate (BER), as well as the time simplicity, the superiority of the fully-complex ELM among the feasible pilot-assisted equalization and the real ELM is revealed for numerous laser linewidths, SNRs, transmission distances, radio frequencies, and OFDM symbol periods. Furthermore, the complex ELM almost achieves the same BER as the CPE compensation, which decreases the transmission rate.…”

Section: Introductionmentioning

confidence: 99%

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Extreme Learning Machines to Combat Phase Noise in RoF-OFDM Schemes

et al. 2019

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Radio-over-fiber (RoF) orthogonal frequency division multiplexing (OFDM) systems have been revealed as the solution to support secure, cost-effective, and high-capacity wireless access for the future telecommunication systems. Unfortunately, the bandwidth-distance product in these schemes is mainly limited by phase noise that comes from the laser linewidth, as well as the chromatic fiber dispersion. On the other hand, the single-hidden layer feedforward neural network subject to the extreme learning machine (ELM) algorithm has been widely studied in regression and classification problems for different research fields, because of its good generalization performance and extremely fast learning speed. In this work, ELMs in the real and complex domains for direct-detection OFDM-based RoF schemes are proposed for the first time. These artificial neural networks are based on the use of pilot subcarriers as training samples and data subcarriers as testing samples, and consequently, their learning stages occur in real-time without decreasing the effective transmission rate. Regarding the feasible pilot-assisted equalization method, the effectiveness and simplicity of the ELM algorithm in the complex domain are highlighted by evaluation of a QPSK-OFDM signal over an additive white Gaussian noise channel at diverse laser linewidths and chromatic fiber dispersion effects and taking into account several OFDM symbol periods. Considering diverse relationships between the fiber transmission distance and the radio frequency (for practical design purposes) and the duration of a single OFDM symbol equal to 64 ns, the fully-complex ELM followed by the real ELM outperform the pilot-based correction channel in terms of the system performance tolerance against the signal-to-noise ratio and the laser linewidth.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Extreme Learning Machines to Combat Phase Noise in RoF-OFDM Schemes

et al. 2019

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“…The multicarrier multiplexing (MCM) technique such as orthogonal frequency division multiplexing (OFDM) is one such method in the current wireless communication era, which has secured its place in design of future integrated RoF systems due to its sturdiness to multipath fading and chromatic dispersion with bandwidth-efficient high data rate transmission capability. [4][5][6][7] In a conventional OFDM system, the signals are multiplexed at the transmitter and decoded at the receiver by applying inverse fast Fourier transform (IFFT) and fast Fourier transform (FFT), respectively. [8][9][10][11] Another extensively used technology in modern wireless communication arena is multiple-input multiple-output (MIMO), which exploits either the spatial diversity to enhance the wireless system reliability or the spatial multiplexing to increase wireless channel capacity owing to trade-off among multiplexing gain and diversity gain.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

MIMO‐OFDM‐radio over fiber system incorporating higher‐order space‐time block codes

Kaur

Sharma

2019

Micro & Optical Tech Letters

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Radio over fiber (RoF) is an indispensable technology for the amalgamation of microwave‐ and optical communication, which facilitates a flexible access‐network infrastructure proficient to endow with broadband wireless connectivity over an extensive assortment of applications. Achieving ample spectral efficiency in conjunction with excellent link reliability is the austere menace to the design of such prospect‐integrated systems. Moreover, amalgamation of multiple‐input multiple‐output (MIMO) technology with multicarrier multiplexing (MCM) such as orthogonal frequency division multiplexing (OFDM) is a proficient contender for supporting such next‐generation RoF‐based static‐ and mobile‐wireless systems. Earlier, the MIMO‐based multicarrier RoF systems are limited to the use of fourth‐order spatial diversity (2 × 2 antenna package) using the Alamouti code. Subsequently, the authors investigated the aptness and impetus of such integrated multicarrier RoF systems to provide a reliable and spectrally efficient system and proposed an orthogonal space‐time block code (OSTBC) equipped MIMO‐OFDM‐RoF system by incorporating higher order spatial diversity in conjunction with QAM (Quadrature Amplitude Modulation) schemes. The proposed work is carried out for NLOS (non‐line of sight) and LOS (line of sight) scenarios. Furthermore, the demonstrated work elucidates a relative QoS (Quality of Service) explorations of sixth (3 × 2 antenna package) and ninth order spatial diversity (3 × 3 antenna package) and recommend the optimal antenna package as per the requirements of the proposed integrated system in the demonstrated scenarios.

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