Sayed Ehsan Alavi

IEEE 802.15.3c WPAN Standard Using Millimeter Optical Soliton Pulse Generated by a Panda Ring Resonator

A system of microring resonators (MRRs) connected to an optical modified add/drop filter system known as a Panda ring resonator is presented. The optical soliton pulse of 60 GHz frequency band can be generated and used for Wireless Personal Area Network (WPAN) applications such as IEEE 802.15.3c. The system uses chaotic signals generated by a Gaussian laser pulse propagating within a nonlinear MRRs system. The chaotic signals can be generated via a series of microring resonators, where the filtering process is performed via the Panda ring resonator system wherein ultrashort single and multiple optical soliton pulses of 60 GHz are generated and seen at the through and drop ports, respectively. The IEEE 802.15.3c standard operates at the 60 GHz frequency band, and it is applicable for a short distance optical communication such as indoor systems, where the higher transmission data rate can be performed using a high frequency band of the output optical soliton pulses. The single and multi-soliton pulses could be generated and converted to logic codes, where the bandwidths of these pulses are 5 and 20 MHz, respectively. Thus, these types of signals can be used in optical indoor systems and transmission link using appropriate components such as transmitter, fiber optics, amplifier, and receiver.

High-capacity soliton transmission for indoor and outdoor communications using integrated ring resonators

A system consisting of a series of microring resonators, incorporating an add/drop system, is presented in order to create ultra-short spatial and temporal single and multisoliton pulses, which can be used for indoor and outdoor optical communications. Chaotic noise can be generated by a bright soliton pulse propagating inside a nonlinear microring resonator system. The results obtained show that a single temporal and spatial soliton pulse, with full width at half maximums of 75fs, 80fs, 700fs, 4.4ps, and 0.30nm, can be generated. The add/drop system can be used to generate a high number of ultra-short soliton pulses in the ranges of nanometer/second and picometer/second. The simulated multisolitons have full width at half maximums of 16ps, 20pm, 130ps, and 35pm and free spectrum ranges of 500ps, 0.57nm, 3.5ns, and 1.4nm, respectively. The multisolitons generated at the drop port can be used in indoor optical communications, where the ultra-short pulses with a variety of central wavelengths from λ=1550 to λ=1560 from the through port can be multiplexed-demultiplexed along an optical fiber with a length of 50km. The filtered signals can be obtained at the end of the transmission link used for optical outdoor communications. Copyright

All-Optical OFDM Generation for IEEE802.11a Based on Soliton Carriers Using Microring Resonators

The optical carrier generation is the basic building block to implement all-optical orthogonal frequency-division multiplexing (OFDM) transmission. One method to optically generate single and multicarriers is to use the microring resonator (MRR). The MRRs can be used as filter devices, where generation of high-frequency (GHz) soliton signals as single and multicarriers can be performed using suitable system parameters. Here, the optical soliton in a nonlinear fiber MRR system is analyzed, using a modified add/drop system known as a Panda ring resonator connected to an add/drop system. In order to set up a transmission system, i.e., IEEE802.11a, first, 64 uniform optical carriers were generated and separated by a splitter and modulated; afterward, the spectra of the modulated optical subcarriers are overlapped, which results one optical OFDM channel band. The quadrature amplitude modulation (QAM) and 16-QAM are used for modulating the subcarriers. The generated OFDM signal is multiplexed with a single-carrier soliton and transmitted through the single-mode fiber (SMF). After photodetection, the radio frequency (RF) signal was propagated. On the receiver side, the RF signal was optically modulated and processed. The results show the generation of 64 multicarriers evenly spaced in the range from 54.09 to 55.01 GHz, where demodulation of these signals is performed, and the performance of the system is analyzed.

W-Band OFDM Transmission for Radio-Over-Fiber Link Using Solitonic Millimeter Wave Generated by MRR

A system comprises of a W-band (75-110 GHz) optical millimeter (mm)-wave generation using microring resonators (MRRs) and radio-over-fiber (RoF) link architectures is presented for multigigabit data rates demand. The MRRs are used to generate optical mm-wave soliton pulses for W-band applications. To achieve faster transmission speed wirelessly, higher spectral efficiency (SE) and better transmission performance, orthogonal frequency-division multiplexing (OFDM) is used. The results show that the MRRs support W-band optical soliton pulses, which can be used in an OFDM transmission/receiver system. Localized narrow bandwidth soliton pulses within frequencies of 92.2-93.2 GHz can be seen in the throughput port of the Panda system with respect to the full width at half maximum and free spectrum range of 3.5 and 184 MHz, respectively. The error vector magnitude of the system was measured and the viability of the solitonic OFDM-based system for RoF link over 25-Km fiber link and 2-m wireless link was confirmed. The data rate of the system with 16-quadrature amplitude modulation is measured as 43.6 Gb/s and with 10 GHz of bandwidth, the SE is obtained as 4.36 bit/s/Hz.

Towards 5G: A Photonic Based Millimeter Wave Signal Generation for Applying in 5G Access Fronthaul.

5G communications require a multi Gb/s data transmission in its small cells. For this purpose millimeter wave (mm-wave) RF signals are the best solutions to be utilized for high speed data transmission. Generation of these high frequency RF signals is challenging in electrical domain therefore photonic generation of these signals is more studied. In this work, a photonic based simple and robust method for generating millimeter waves applicable in 5G access fronthaul is presented. Besides generating of the mm-wave signal in the 60 GHz frequency band the radio over fiber (RoF) system for transmission of orthogonal frequency division multiplexing (OFDM) with 5 GHz bandwidth is presented. For the purpose of wireless transmission for 5G application the required antenna is designed and developed. The total system performance in one small cell was studied and the error vector magnitude (EVM) of the system was evaluated.

Increment of Access Points in Integrated System of Wavelength Division Multiplexed Passive Optical Network Radio over Fiber

This paper describes a novel technique to increase the numbers of access points (APs) in a wavelength division multiplexed-passive optical network (WDM-PON) integrated in a 100 GHz radio-over-fiber (RoF). Eight multi-carriers separated by 25 GHz intervals were generated in the range of 193.025 to 193.200 THz using a microring resonator (MRR) system incorporating an add-drop filter system. All optically generated multi-carriers were utilized in an integrated system of WDM-PON-RoF for transmission of four 43.6 Gb/sec orthogonal frequency division multiplexing (OFDM) signals. Results showed that an acceptable BER variation for different path lengths up to 25 km was achievable for all four access points and thus the transmission of four OFDM channels is feasible for a 25 km standard single mode fiber (SSMF) path length.

W-Band OFDM for Radio-over-Fiber Direct-Detection Link Enabled by Frequency Nonupling Optical Up-Conversion

A system involving W-band (75-110 GHz) optical millimeter (mm)-wave generation using the external optical modulator (EOM) in a radio-over-fiber (RoF) link is presented for satisfying the requirements for multi-gigabit-per-second data rates. A 90-GHz mm-wave signal was generated by a nonupling (nine times) increase in only a 10-GHz local oscillator by biasing the EOM at its zero level and choosing an appropriate modulation index. To achieve a fast transmission speed wirelessly, high spectral efficiency (SE), and better transmission performance, orthogonal frequency-division multiplexing (OFDM) is used. The bit error rate (BER) and error vector magnitude (EVM) of the system were measured for three different fiber lengths and for a wireless distance of 1-5 m. The results show that the system with the SE of ~4 (b/s)/Hz and 16-ary quadrature amplitude modulation (QAM) 40-GB/s OFDM signals can be received by the end user with BER less than 3.8 × 10-3 and EVM less than 25% over a 50-km optical fiber and 3-m wireless link.

All-Optical Generation of Two IEEE802.11n Signals for 2

A radio-over-fiber system capable of very spectrally efficient data transmission and based on multiple-input multiple-output (MIMO) and orthogonal frequency-division multiplexing (OFDM) is presented here. Carrier generation is the basic building block for implementation of OFDM transmission, and multicarriers can be generated using the microring resonator (MRR) system. A series of MRRs incorporated with an add/drop filter system was utilized to generate multicarriers in the 193.00999-193.01001-THz range, which were used to all-optically generate two MIMO wireless local area network radio frequency (RF) signals suitable for the IEEE802.11n standard communication systems, and single wavelengths at frequencies of 193.08, 193.1, and 193.12 THz with free spectral range of 20 GHz used to optically transport the separated MIMO signals over a single-mode fiber (SMF). The error vector magnitude (EVM) and bit error rate of the overall system performance are discussed. Results show that the generated RF signals wirelessly propagated through the MIMO channel using the 2 × 2 MIMO Tx antennas. There is an acceptable EVM variation for wireless distance lower than 70, 30, and 15 m. It can be concluded that the transmission of both MIMO RF signals is feasible for up to a 50-km SMF path length and a wireless distance of 15 m.

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The novel technique for generating the robust, ultra-wideband (UWB) signal in the optical domain using a mode-locked laser incorporated with an add-drop microring resonator filter is presented. In order to enable the down conversion of the UWB signal to the RF domain, two wavelength ranges 1553.72 and 1553.92 nm, which are 24.65 GHz apart from each other, are used. These wavelengths were generated based on a single longitudinal mode (SLM) dual-wavelength fiber laser in a laser ring cavity. The upper wavelength of the generated dual-wavelength laser is modulated with the UWB spectrum using an optical carrier suppression (OCS) scheme and the lower wavelength is kept unmodulated. After beating the modulated and unmodulated wavelength by launching into the photodiode, the 24 GHz UWB signal can be generated to be applied to UWB over fiber (UWBoF) technology. The error vector magnitude (EVM) for the signal transmission was calculated and the EVM below 10% is achieved for 25 Km optical and 20 m wireless links.

2 MIMO-RoF via MRR System

Microring resonators (MRRs) can be used to generate optical millimetre-wave solitons with a broadband frequency of 40-60 GHz. Non-linear light behaviours within MRRs, such as chaotic signals, can be used to generate logic codes (digital codes). The soliton signals can be multiplexed and modulated with the logic codes using an orthogonal frequency division multiplexing (OFDM) technique to transmit the data via a network system. OFDM uses overlapping subcarriers without causing inter-carrier interference. It provides both a high data rate and symbol duration using frequency division multiplexing over multiple subcarriers within one channel. The results show that MRRs support both single-carrier and multi-carrier optical soliton pulses, which can be used in an OFDM based on whether fast Fourier transform or discrete wavelet transform transmission/receiver system. Localised ultra-short soliton pulses within frequencies of 50 and 52 GHz can be seen at the throughput port of the panda system with respect to full-width at half-maximum (FWHM) and free spectrum range of 5 MHz and 2 GHz, respectively. The soliton pulses with FWHMs of 10 MHz could be generated at the drop port. Therefore, transmission of data information can be performed via a communication network using soliton pulse carriers and an OFDM technique.