Novel Vestigial Sideband Modulation Scheme to Enhance the SNR in Radio Over Fiber Systems

Udvary, Eszter; Parajuli, Hum Nath

doi:10.13164/re.2017.0961

Cited by 3 publications

(6 citation statements)

References 16 publications

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“…Based on the measurement results, we obtain the MZM characteristic curve at QBP (1.5 V; 0.425 mW). Meanwhile, the model in (13) produces an ideal cosine-squared curve; therefore, if the initial phase model is based on [51], and from the measurement results, we can obtain a phase shift constant through (20) when there is no RF signal.…”

Section: B Mzm Output Power Modelmentioning

confidence: 99%

“…Previous technique add a wavelength division multiplexing (WDM) after the MZM and a coupler before MZM [50]. Other method uses a phase modulation before the signal enters the MZM input [48], [51]. However, these linear improvement require the installation of additional devices in the optical link [39]- [51].…”

Section: Introductionmentioning

confidence: 99%

“…Other method uses a phase modulation before the signal enters the MZM input [48], [51]. However, these linear improvement require the installation of additional devices in the optical link [39]- [51]. These devices lead to intermodulation distortion and require an additional solution for either the optical link or the process after the photodiode.…”

Section: Introductionmentioning

confidence: 99%

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Maximum RF Input Signal on the Electro-Optic Modulator Transmission Boundary Area for Harmonic Distortion Compensation in Analog Radio Over Fiber

2022

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In this study, we perform an analytical investigation of the electro-optic (EO), Mach-Zehnder modulator (MZM) transmission boundary area with a nonlinear model. We propose a nonlinear model that represents the allowable RF input amplitude within the MZM transmission boundary area. We investigate the maximum RF input amplitude and confine its harmonics using nonlinear model theory, RoF simulation, and MZM characteristic experiments. The maximum RF input amplitude in the MZM transmission boundary area is a convenient technique that can confine harmonics without an optical amplifier, optical filter, or other optical devices in RoF links. We select several RF input amplitudes within the MZM boundary area and account for harmonic distortion in the investigation. The RF input amplitude is 0.8 times of the EO modulator switching voltages. The boundary areas show that near the switching voltage value, the harmonics-to-main RF ratio (HMR) is less than 10%. Furthermore, the maximum RF inputs are still appropriate for QPSK modulation. We evaluate the nonlinear model of these modulation signals in terms of the error vector magnitude and constellation diagram. After considering the optical fiber impairment, thermal noise, and harmonics distortion in the nonlinear model with the modulation signal of QPSK, the ACLR and EVMs satisfy the 3GPP specification. The nonlinear models are appropriate for a small or medium sized of radioover-fiber links.

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Section: B Mzm Output Power Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Maximum RF Input Signal on the Electro-Optic Modulator Transmission Boundary Area for Harmonic Distortion Compensation in Analog Radio Over Fiber

2022

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“…n=−∞ e jπγ + e jnθ . j n .J n (m).e j2π( f c +n f m )t (19) From Equation (19), it can be seen that the optical signal spectrum of the DD-MZM output with CA comprises an optical carrier with infinite sideband order. Various forms of modulation schemes can still be generated by setting the parameter θ and γ.…”

Section: Xtx(t) Is Given Bymentioning

confidence: 99%

“…The reduction in DPF can be overcome using optical single-sideband (OSSB) modulation. OSSB modulation has advantages such as not requiring frequency translation [19] or inconvenient phase receiver adjustment. OSSB modulation scheme can be generated by filtering one of the sideband modulated optical signals [20].…”

Section: Introductionmentioning

confidence: 99%

Asymmetric Carrier Divider with an Irregular RF Phase on DD-MZ Modulator for Eliminating Dispersion Power Fading in RoF Communication

2020

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The main problem of intensity modulation (IM) in radio-over-fiber (RoF) communication is dispersion power fading (DPF), which occurs when the signal is transmitted through a dispersive link that causes a sideband cancelation effect. The DPF level of the RoF link is determined by the deviation factor (DF). The optical single-sideband (OSSB) modulation scheme, which is generated by driving one of the dual-drive Mach–Zehnder modulators (DD-MZMs), is usually used to overcome DPF. The DF value of OSSB modulation at modulation index m = 0.1 increases from 0.008 to 0.930 at m = 1. It can be said that this method is only effective at reducing DF at low m. However, as well-known information of the DD-MZM system, high-efficiency optic–electric conversions can be obtained at high m values, but DF will increase. Therefore, reducing the DPF value for high m ≥ 0.1 is interesting. It is known that in wireless communication, to reduce the impact of fading, direct signals are amplified and signals with irregular phases are used. Moreover, this paper proposes the DD-MZM with an asymmetric carrier divider as a direct signal and combines it with an irregular radio frequency (RF) phase to reduce the DPF at high m. The carrier that is generated by laser diode (LD) power (PIN) is divided asymmetrically as power modulation (PDD-MZM) and carrier arm (CA) power (PCA). Furthermore, the minimum DF is obtained when the PIN is separated as 75% for PCA and 25% for PDD-MZM with an irregular RF signal of θ = 48° and a bias point value of γ = ¾. As a result, with the same power as OSSB, this proposed structure produces DF at m = 0.1 and m = 1 with values of 0.008 and 0.03, or it can reduce DF of 96.7% at m = 1. The mathematical model and simulation model have very good agreement, which validates the proposed method.

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A Single DD-MZM for Generating Vestigial Sideband Modulation Scheme in Radio Over Fiber Systems

Ujang

Wibisono

2018

2018 2nd International Conference on Electrical Engineering and Informatics (ICon EEI)

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Novel Vestigial Sideband Modulation Scheme to Enhance the SNR in Radio Over Fiber Systems

Cited by 3 publications

References 16 publications

Maximum RF Input Signal on the Electro-Optic Modulator Transmission Boundary Area for Harmonic Distortion Compensation in Analog Radio Over Fiber

Maximum RF Input Signal on the Electro-Optic Modulator Transmission Boundary Area for Harmonic Distortion Compensation in Analog Radio Over Fiber

Asymmetric Carrier Divider with an Irregular RF Phase on DD-MZ Modulator for Eliminating Dispersion Power Fading in RoF Communication

A Single DD-MZM for Generating Vestigial Sideband Modulation Scheme in Radio Over Fiber Systems

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