We investigate the feasibility of implementing a mobile fronthaul network (MFN) based on radio-over-fiber (RoF) technology for fifth generation wireless communication systems cost effectively by using either directly modulated lasers (DMLs) or electroabsorption (EMLs) operating in 1.55-μm window. The results show that performance RoF-based MFN implemented DMLs is primarily limited composite second-order (CSO) distortions arising from interplay between DML's adiabatic chirp and fiber's...

We explore the possibility of utilizing 1.55-μm directly modulated lasers (DMLs) for optical access networks operating at 28 Gb/s per wavelength. For this purpose, we attempt to maximize power budgets 28-Gb/s duobinary and four-level pulse amplitude modulation (PAM-4) signals generated from a DML without using amplifiers or dispersion compensation modules. experimental investigation, set bias current far above threshold current, optimize extinction ratio signals, utilize electrical...

We propose and demonstrate a simple composite second-order (CSO) cancellation technique based on the digital signal processing (DSP) for radio-over-fiber (RoF) transmission system implemented by using directly modulated lasers (DMLs). When RoF is DMLs, its performance could be limited CSO distortions caused interplay between DML's chirp fiber's chromatic dispersion. present theoretical analysis of these nonlinear show that they can suppressed at receiver DSP. To verify effectiveness proposed...

We demonstrate the transmission of 51.56-Gb/s on-off keying (OOK) signals generated by using a 1.55-μm directly modulated laser (DML) over 15-km long standard single-mode fiber. In this experiment, duobinary electrical equalizer based on finite-impulse-response filter is used at receiver to increase dispersion-limited distance. evaluate performances OOK with respect distance frequency response analysis proposed system. This result explain why it effective utilize equalization (instead binary...

Magnetic properties of sol-gel and conventional ceramic processed Ba3Co2Fe2O41 hexaferrite were investigated compared for terrestrial digital multimedia broadcasting (T-DMB) antenna application. All the synthesized powder sintered body showed almost single Z-phase. The loss tan δ Co2Z was 0.010 at 200 MHz, while 0.068. ωd (resonance frequency domain wall) ωs spin components) hexaferrites estimated to be 10 1160 MHz 17 1025 respectively. difference between (1150 MHz) is wider than that (1008...

Z-type barium hexaferrite particles were synthesized by a one-step mixing-calcination process (MCP) and its magnetic properties characterized compared to the sol-gel (SGP) conventional ceramic (CCP) processed Ba with two-step calcination. We have used 71.2% pure M-type (BaFe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sub> O xmlns:xlink="http://www.w3.org/1999/xlink">19</sub> ) 83.8% Y-type (Ba...

Performance of inverted F meander antenna with a lossy ferrite film was investigated and compared to air-core the same design. We have fabricated using 3μm thick plated Ni0.21Zn0.45Fe2.34O4. Loss tanδμ about 1.5 around 500MHz. It found that bandwidth significantly increased by use ferrite, while radiation efficiency (RE) decreased. However, RE increases as thickness decreases below 10μm. The fractional be 13.8%, which shows 431% an antenna. center frequency (fc) for decreased from...

We propose to utilize the filtered Gaussian phase dither technique for effective suppression of multipath- interference (MPI) noises caused by multiple bad fiber connectors in mobile fronthaul network (MFN) based on radio-over- (RoF) technology. first evaluate viable performances RoF-based MFN 5G wireless communication systems using this and deduce required bandwidth modulation depth signal MPI numerical simulations. The results show that, proposed technique, it is possible suppress ~10 dB...

We design a heterogeneous 12-core 4-LP-mode fiber having two different types of cores and trench-assisted graded-index profiles. For the optimum index profiles these cores, we first investigate impacts various geometric parameters on effective refractive each LP mode, maximum differential modal delay (DMD), bending losses guiding higher order modes. then 4-LP mode cladding diameter 242 μm. The numerical analyses based coupled-mode equation show that inter-core crosstalk levels proposed are...

We report on technical challenges associated with the use of directly modulated lasers in mobile fronthaul networks based radio-over-fiber (RoF) technology. In particular, effects dispersion-induced RF power fading and multi-path interference are investigated through theoretical experimental analyses for RoF-based transmission system implemented by using lasers.

We demonstrate the transmission of 56-Gb/s PAM-4 signal over 20-km long SSMF by using a 1.55-μm DML without optical dispersion compensation. Instead, linear electric equalizer is used for compensation dispersion-induced waveform distortions.

We propose and demonstrate a common public radio interface (CPRI)-compliant 25.2923-Gb/s mobile fronthaul network for long term evolution-advanced (LTE-A) systems. In order to meet the CPRI specifications stringent latency requirement of LTE-A cost-effectively, we use synchronous time-division-multiplexing, forward-error correction, electrical equalization techniques. To enhance cost-effectiveness, also an electroabsorption-modulated laser exploit possibility using simple modulation formats...

We analyze the inter-core crosstalk in homogeneous multi-core two-mode fibers (MC-TMFs) under bent condition by using coupled-mode equations. In particular, we investigate effects of intra-core mode coupling on for two different types MC-TMFs at various bending radii. The results show that homo-mode LP(11) is dominant gentle fiber due to its large effective area. However, as becomes tight, significantly enhanced and consequently makes all levels comparable each other regardless mode. A...

Optics has advanced through centuries of research into the fundamental properties light and its interactions with matter. Within this rich history, one optical component stands out: diffraction grating. Liquid crystals (LCs) have emerged as promising candidates in gratings. LCs are versatile adaptable materials influenced by various external factors. Diffractive LC grating devices can be produced methods such photo alignment, using polymer walls, or employing patterned electrodes. However,...

We examine the feasibility of utilizing RoF-based fronthaul network for next-generation mobile communication systems. For this purpose, we evaluate effects dispersion-induced RF power fading, CSO distortions induced by interplay between laser chirp and fiber dispersion, MPI noises optical reflections, etc.

We propose to utilize the digital optical phase conjugation (D-OPC) technique for compensation of mode crosstalk in mode-division-multiplexed (MDM) transmission system. To realize D-OPC technique, we send CW light from receiver side, measure its wavefront at transmitter and then, transmit phase-conjugated signal receiver. By using this demonstrate four LP modes, each carrying 10-Gb/s ON-OFF keying signals, over a 100-m long few-mode fiber link. These signals are detected by direct-detection...

We propose to implement a 2-channel optical-time-division-multiplexed (OTDM) system for short-reach optical interconnects by using sinusoidally modulated light source instead of complicated mode-locked laser as an input pulse source. In this system, the OTDM signal is obtained bit-interleaving two return-to-zero (RZ) signals generated light. operate these RZ in orthogonal in-phase and quadrature domains avoid unwanted beat components. After transmission, detected single photodetector, then...

We propose a blind compensation technique to mitigate the waveform distortions caused by nonlinear transfer function of electro-absorption modulated laser (EML) in radio-over-fiber (RoF) system. The proposed automatically adjusts its coefficients using magnitude measured at right outside signal's bandwidth. By technique, we successfully demonstrate transmission twelve 198-MHz filtered-orthogonal-frequency-division-multiplexed (f-OFDM) signals 256 quadrature amplitude modulation (QAM) format...

We propose the generation of a high-speed four-level pulse amplitude modulated (PAM4) signal by combining two on-off keying (OOK) signals obtained overdriving Mach-Zehnder modulators (MZMs). By using this method, we can overcome limited modulation bandwidth MZM and generate PAM4 (faster than generated modulating an with electrical signal). For demonstration, 95-Gb/s OOK from bandwidth-limited having 3-dB only 10.5 GHz. In comparison, when conventional it is not possible to increase bit rate...

The effect of Mn and/or Co doping in Ni–Mn–Co ferrite on the static, dynamic magnetic properties, and thermal stability were investigated for high frequency microwave applications up to gigahertz range. Saturation magnetization coercivity increased with substitution Co, respectively. Both substituted exhibited higher factor rather than Ni–Mn Ni–Co ferrites. highest was achieved be −12.0×10−4 °C/ppm Ni0.93Mn0.05Co0.02Fe2O4. second highest, −11.88×10−4 °C/ppm, measured...

We report on the adaptive cancellation technique of dispersion-induced composite second-order (CSO) distortions for use in radio-over-fiber (RoF) systems implemented by using directly modulated lasers (DMLs). The proposed utilizes magnitude CSO measured at outside signal's bandwidth as a cost function steepest descent algorithm. As result, this can blindly cancel out without necessity measuring any device and fiber parameters used RoF system. effectiveness is confirmed link 1.55-μm DML...

There have been substantial efforts to implement high-speed (>10 Gb/s) upstream transmission using reflective semiconductor optical amplifiers (RSOAs) in a coherent wavelength-division-multiplexed (WDM) passive network (PON). In such network, it is necessary estimate the carrier phase of signal retrieve phase-modulated information created by RSOA. However, due severe waveform distortions caused limited modulation bandwidth RSOA (typically less than 3 GHz), previously reported estimation...

We evaluate possibility of utilizing the mode-field matched center-launching (MCL) technique in 850-nm band. For this purpose, we realize MCL by fusion-splicing HI-780 pigtail fiber transmitter to OM2-type transmission multi-mode (MMF). The results show that can achieve high coupling efficiency >92% optimizing splicing conditions such as arc-discharge duration and fiber-push distance. confirm that, case technique, frequency-response characteristics MMF link becomes almost identical...

Abstract In high‐field magnetic resonance imaging (MRI) system, the signal‐to‐noise ratio of MR signal is so high that receiver frequently cannot cover full dynamic range signal. Although this problem can be overcome by using a compander (compressor and expander) composed logarithmic amplifiers ROM table to retrieve nonlinearity or simply increasing number bits analog‐to‐digital converter, methods costly complex even impossible for most commercial systems. addition, spectrometer has...