Channel independent precoding technique has been widely used in optical discrete multi-tone (DMT) transmission systems to compensate unbalanced impairments induced by bandwidth limitations and imperfect frequency responses of electrical/optical devices various interferences. However, the comparison different techniques terms peak-to-average power ratio (PAPR) reduction, nonlinear distortion tolerance, implementation complexity, bit error rate (BER) improvements not fully studied. In this...

We experimentally demonstrate what we believe to be a novel wavelength division multiplexing–passive optical networking (WDM-PON) architecture compatible with 60 GHz radio-over-fiber systems simultaneously provide wireless or wired services. place each wireless/wire-line channel in one WDM slot carry 2.5 Gb∕s orthogonal frequency multiplexing (OFDM) signal and reuse downstream wavelengths of the wire-line channels for uplink by an on–off-keying modulation format signal. For independent...

In this paper, to the best of our knowledge, is first time that generation and reception online software-reconfigurable real-time 4/16/64-quadrature amplitude modulation (QAM)-encoded forward error correction (FEC)-enabled orthogonal frequency-division multiplexing (OFDM) signals over X-band fiber-over-radio-based upstream links has been demonstrated. A Reed-Solomon code, i.e., RS (288, 256), with symbol interleaving/deinterleaving applied enhance bit-error-rate (BER) performance. The...

Digital-to-analog converters (DACs) are widely used in bandwidth-limited visible-light communication (VLC) systems for high spectral-efficiency multi-carrier signal generation. To reduce the implementation complexity of transmitter, a digital 1-bit low-pass delta-sigma modulation (DSM)-enabled DAC-free filter-bank (FBMC) generation scheme is proposed and experimentally investigated red light-emitting diode-based VLC system. In this scheme, one field programmable gate array gigabit...

We propose an optical line terminal (OLT)-centralized sampling frequency offset (SFO) compensation scheme for adaptively-modulated OFDM-PON systems. By using the proposed SFO scheme, phase rotation and inter-symbol interference (ISI) caused by SFOs between OLT multiple network units (ONUs) can be centrally compensated in OLT, which reduces complexity of ONUs. Firstly, optimal fast Fourier transform (FFT) size is identified intensity-modulated direct-detection (IMDD) OFDM system presence SFO....

We report a radio-over-fiber (ROF) access network with multiple high-repetive frequency mm-wave signals generation utilizing dual-parallel Mach-Zehnder modulator (DP-MZM) and an semiconductor optical amplifier (SOA) for base stations (BSs). In the scheme, at central station (CS), signal pump interval of 8<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">f</mml:mi></mml:mrow><mml:mrow><mml:mi...

Filter bank multicarrier with offset quadrature amplitude modulation (FBMC/OQAM) can provide higher spectral efficiency and lower out-of-band spectral/power leakages than conventional orthogonal frequency-division multiplexing QAM (OFDM/QAM). Due to the imperfect frequency response of electrical/optical devices various interferences, significant subcarrier SNR fluctuation may result in poor bit error rate (BER) performance. In this work, channel-independent precoding techniques are employed...

Sampling frequency offset (SFO) between digital-to-analog converters and analog-to-digital will seriously degrade the receiver performance of asynchronous direct-detection optical OFDM (DDO-OFDM), due to SFO-induced inter-symbol interference, inter-channel phase rotation. In this letter, a simple overhead-free SFO compensation scheme enabled by differential detection (ISDD) is proposed experimentally demonstrated in short-reach low-cost directly modulated laser-based DDO-OFDM system with an...

In this paper, a very low power modified current-reused quadrature voltage-controlled oscillator (QVCO) is proposed with the back-gate coupling technique for signal generation. By stacking switching transistors in series like cascode, QVCO can be constructed totem-pole manner to reuse dc biasing current and lower consumption. utilizing back-gates of as terminals achieve outputs, coupled improves phase noise reduces consumption compared conventional transistor based topology. Together...

Modulation bandwidth limitation is one of the major drawbacks in light-emitting diode (LED)-based visible light communication (VLC) systems. Various advanced physical-layer modulation formats with digital/analog pre-equalization or adaptive techniques are usually employed to improve transmission rate VLC In this Letter, we use a radio frequency (RF) digital-to-analog converter (DAC) directly realize signal without additional digital analog processing. addition, low-complexity real-valued...

Optical discrete multi-tone (DMT) is one type of direct-detection optical orthogonal frequency-division multiplexing (DDO-OFDM), and it more suitable for cost-sensitive access networks interconnections due to its simple structure. In DMT transmitter, inverse fast Fourier transform (IFFT) an essential function achieving OFDM modulation, input data are constrained have Hermitian symmetry (HS). To support high-speed signal generation, a fully-parallel implementation IFFT preferable. However,...

In this paper, we propose a cost-efficient, polarization-insensitive and widely-tunable wavelength conversion scheme for orthogonal frequency division multiplexing (OFDM) signal based on four-wave mixing (FWM) in semiconductor optical amplifier (SOA). scheme, electrical OFDM directly drives modulated laser (DML) to achieve intensity modulation, then the lightwave pump are coupled injected into polarization-diversity structure performing FWM SOA. The analytical results show that proposed is...

Digital-to-analog converters (DAC) with a high sample rate and large bandwidth are preferred to achieve data-rate signal generation in an optical discrete multi-tone (DMT) system. Clock leakage is one of the imperfections high-speed DACs. One or more data subcarriers generated DMT may be interfered by additional clock tone, which cause error floor bit (BER) performance. In this work, pre-equalized 16/32QAM-DMT signals net up 121 Gbit/s 80 GSa/s DAC at 20 GHz. Two simple compensation (CLC)...

Orthogonal frequency-division multiplexing-based passive optical networks (OFDM-PON) can provide high spectral efficiency and flexible two-dimensional bandwidth allocation by assigning subcarriers (SCs) time slots. The direct-modulation direct-detection (DM-DD) OFDM with Hermitian symmetry constraint has simple hardware implementation, low cost, power consumption compared to coherent detection is more suitable for cost-sensitive PON. In such a symmetric (HS-OFDM), only half of the SCs be...

We have proposed a scheme of radio-over-fiber (RoF) system employing dual-parallel Mach–Zehnder modulator (DP-MZM) based on four-wave mixing (FWM) in semiconductor optical amplifier (SOA). In this scheme, the pump and signal are generated by properly adjusting direct current bias, modulation index DP-MZM, phase difference between sub-MZMs. Because deriving from same wave, polarization states two lightwaves copolarized. The single-pump FWM is insensitive. After filtering, millimeter-wave with...

The primary objective of this paper is to apply the CHATUE algorithm, presented in Part-1 article, multi-user Single Carrier Frequency Division Multiple Access (SC-FDMA) Systems. algorithm connects turbo equalizers neighboring time absence Cyclic Prefix or Guard Interval, where latest version reduced complexity equalization technique, Domain Soft Cancellation Minimum Mean Square Error utilized not only mitigate inter-carrier interference but also eliminate inter-block interferences from...

The time-interleaved analog-to-digital converter (TI-ADC) is a good option to realize high-speed data conversion for both single-carrier and multi-carrier optical communication systems. Offset mismatch one of its drawbacks, which causes distortion in the sampled degrades bit error rate (BER) performance In this article, low-complexity online digital offset compensation (OMC) scheme based on time-domain averaging proposed implemented with commercial off-the-shelf field programmable gate array...