On-off Keying Modulation Research Articles

Investigation on the Performance of FSO Communication Link Under Various System Parameters

Optical Wireless Communication (OWC) also known as Free Space Optics (FSO) technology has many advantages such as availability of license-free spectrum, low deployment cost, large modulation bandwidth, low consumption of power, and small size. In this paper, the investigation on the performance of free space optical communication link has been done for different system parameters and transmission windows using OOK (on-off keying) modulation scheme. The performance of the system has been analyzed using Q Factor and SNR of the received signal as the performance metric. Also, the effect of atmospheric attenuation on the performance of the system has been analyzed by varying the link distance between the transmitter and the receiver for a specified transmission power level and bit rate. The performance of the system has also been investigated under different data transmission rates and transmission power levels using OPTISYSTEM simulation software.

A Millimeter-Wave Digital Link for Wireless MRI.

A millimeter (mm) wave radio is presented in this work to support wireless MRI data transmission. High path loss and availability of wide bandwidth make mm-waves an ideal candidate for short range, high data rata communication required for wireless MRI. The proposed system uses a custom designed integrated chip (IC) mm-wave radio with 60 GHz as radio frequency carrier. In this work, we assess performance in a 1.5 T MRI field, with the addition of optical links between the console room and magnet. The system uses ON-OFF keying (OOK) modulation for data transmission and supports data rates from 200 Mb/s to 2.5 Gb/s for distances up-to 65 cm. The presence of highly directional, linearly polarized, on-chip dipole antennas on the mm-wave radio along with the time division multiplexing (TDM) circuitry allows multiple wireless links to be created simultaneously with minimal inter-channel interference. This leads to a highly scalable solution for wireless MRI.

Achievable Strength-Based Signal Detection in Quantity-Constrained PAM OOK Concentration-Encoded Molecular Communication.

In this paper, the expressions of achievable strength-based detection probabilities of concentration-encoded molecular communication (CEMC) system have been derived based on finite pulsewidth (FP) pulse-amplitude modulated (PAM) on-off keying (OOK) modulation scheme and strength threshold. An FP-PAM system is characterized by its duty cycle α that indicates the fraction of the entire symbol duration the transmitter remains on and transmits the signal. Results show that the detection performance of an FP-PAM OOK CEMC system significantly depends on the statistical distribution parameters of diffusion-based propagation noise and intersymbol interference (ISI). Analytical detection performance of an FP-PAM OOK CEMC system under ISI scenario has been explained and compared based on receiver operating characteristics (ROC) for impulse (i.e., spike)-modulated (IM) and FP-PAM CEMC schemes. It is shown that the effects of diffusion noise and ISI on ROC can be explained separately based on their communication range-dependent statistics. With full duty cycle, an FP-PAM scheme provides significantly worse performance than an IM scheme. The paper also analyzes the performance of the system when duty cycle, transmission data rate, and quantity of molecules vary.

An 20-Gb/s W-Band OOK CMOS Receiver for High-Speed Wireless Interconnect

This letter presents a high-speed and low-power consuming on-off keying (OOK) receiver implemented on 65-nm Si-CMOS process. The receiver uses OOK modulation for the low-power consumption and operates at a high-data rate due to wide-bandwidth circuitry. The receiver consists of a wideband low-noise amplifier (LNA), a gain-boosting detector and a third-order active feedback amplifier. The receiver consumes 46 mW at 1 V supply and occupies 0.64 mm2 including all pads. The receiver achieves 20 Gb/s at a bit-error rate (BER) less than $10^{\mathrm {-11}}$ for $2^{7}$ -1 pseudorandom binary sequence (PRBS). The sensitivity is −29 dBm at 20 Gb/s data rate, and the energy per bit exhibits 2.3 pJ/bit. To the best of our knowledge, this receiver achieves the highest data rate at the single carrier modulation and the lowest energy per bit among the previously published millimeter-wave Si-CMOS OOK receivers.

Ultrabroad linewidth orange-emitting nanowires LED for high CRI laser-based white lighting and gigahertz communications.

Group-III-nitride laser diode (LD)-based solid-state lighting device has been demonstrated to be droop-free compared to light-emitting diodes (LEDs), and highly energy-efficient compared to that of the traditional incandescent and fluorescent white light systems. The YAG:Ce3+ phosphor used in LD-based solid-state lighting, however, is associated with rapid degradation issue. An alternate phosphor/LD architecture, which is capable of sustaining high temperature, high power density, while still intensity- and bandwidth-tunable for high color-quality remained unexplored. In this paper, we present for the first time, the proof-of-concept of the generation of high-quality white light using an InGaN-based orange nanowires (NWs) LED grown on silicon, in conjunction with a blue LD, and in place of the compound-phosphor. By changing the relative intensities of the ultrabroad linewidth orange and narrow-linewidth blue components, our LED/LD device architecture achieved correlated color temperature (CCT) ranging from 3000 K to above 6000K with color rendering index (CRI) values reaching 83.1, a value unsurpassed by the YAG-phosphor/blue-LD counterpart. The white-light wireless communications was implemented using the blue LD through on-off keying (OOK) modulation to obtain a data rate of 1.06 Gbps. We therefore achieved the best of both worlds when orange-emitting NWs LED are utilized as "active-phosphor", while blue LD is used for both color mixing and optical wireless communications.

Novel Visible Light Communication Approach Based on Hybrid OOK and ACO-OFDM

In this letter, we present a novel hybrid intensity modulation and direct detection communication system, which integrates asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM) and on-off keying (OOK) modulation schemes. First, the negative ACO-OFDM is proposed based on the conventional ACO-OFDM system to accommodate the on case with direct current in the OOK modulation, while the ACO-OFDM can match the off case in the OOK modulation. Therefore, the novel hybrid system combines the ACO-OFDM and OOK modulation schemes, while the signals can be recovered at the receiver to support the different qualities of service with high spectral efficiency and can be adapted to various receivers with different complexities. Simulation results are reported for the visible light channel and show that both the ACO-OFDM and OOK signals can be well recovered.

Ultra-wideband signal generator based on cross gain modulation effect in a distributed feedback laser

In this paper, a novel scheme to generate ultra-wideband (UWB) signals based on cross-gain modulation (XGM) effect in a DFB laser is proposed and experimentally demonstrated, and the modulation and transmission of the UWB signals are also experimentally investigated. In the proposed system, a gain-switched laser (GSL) is used as master laser (ML) and the optical pulses from the ML are optically injected into a DFB laser, which is used as slave laser (SL). By proper system configuration, UWB monocycle, doublet or triplet UWB signals can be generated after the balanced photodiode (BPD) detection. Besides, other modulation formats can also be realized, such as on-off keying (OOK) and pulse amplitude modulation (PAM) by properly modulating the ML optical pulses. Finally, fiber transmission of the modulated UWB signals is experimentally investigated, and it is shown that the UWB signals can be well maintained after 40km optical fiber transmission.

Experimental Study of Red-, Green-, and Blue-Based Light Emitting Diodes Visible Light Communications for Micro-Projector Application

ABSTRACTIn this research, an experimental short-range visible light communication link using red-, green-, and blue-based light-emitting diodes (LEDs) for portable micro-projector applications is presented. A Reconfigurable design of a post-equalizer aimed to improve the inherent narrow modulation bandwidth of red-, green-, and blue-based LEDs has been experimentally implemented, and its effectiveness with optical filters at the receiver is investigated. Reflective liquid-crystal-on-silicon-based micro-projection architecture, widely used in portable micro-projectors, was set up to evaluate the proposed visible light communication system. The measurement results demonstrated that a significant aggregative bandwidth improvement of 162 MHz as well as an aggregative data transmission rate of nearly 400 Mb/s can be achieved by using a non-return-to-zero–on-off keying (NRZ–OOK) modulation scheme based on only one polarization state of incident light without any offline signal processing.

A Fully Integrated IEEE 802.15.7 Visible Light Communication Transmitter With On-Chip 8-W 85% Efficiency Boost LED Driver

This paper presents an IEEE 802.15.7 Physical Layer I (PHY-I) standard compliant visible light communication (VLC) transmitter system-on-a-chip (SoC), enabling the use of ordinary white LED lights as beacons or broadcasters for location-based applications. The mixed-signal SoC integrates a baseband digital signal processing (DSP) unit, a VLC modulator, and a switching boost LED driver with an on-chip power MOSFET. The DSP unit supports various coding schemes as well as both the on-off keying (OOK) modulation and the variable pulse-position modulation specified in the aforementioned standard. The boost LED driver is designed to power a matrix of 4 × 5 LEDs using Li-ion batteries for portable applications. The SoC simultaneously supports VLC and LED illumination with nine dimming levels. Implemented in a 0.35-μm CMOS process with 20-V devices, the SoC achieves a measured VLC data rate of up to 266 kb/s at a package error rate (PER) < 10% using a 211 −1 PRBS (pseudo random binary sequence) input. The communication distance measured is more than 2 m using no optical lens with the link efficiency of 5 nJ/bit. From an input at 3–5 V, the boost converter generates an output at 6–20 V with a 92% peak efficiency and an 8-W rating.

0.18㎛ CMOS 공정을 이용한 WBAN용 비동기식 IR-UWB RF 송수신기

In this paper, an Impulse Radio-Ultra Wide band RF Transceiver for WBAN applications is implemented in CMOS technology. The designed RF transceiver support 3-5GHz UWB low band and employs OOK(On-Off Keying) modulation. The receiver employs non-coherent energy detection architecture to reduce complexity and power consumption. For the rejection of the undesired interferers and improvement of the receiver sensitivity, RF active notch filter is integrated. The VCO based transmitter employs the switch mechanism. As adapt the switch mechanism, power consumption and VCO leakage can be reduced. Also, the spectrum mask is always same at each center frequency. The measured sensitivity of the receiver is -84.1 dBm at 3.5 GHz with 1.579 Mbps. The power consumption of the transmitter and receiver are 0.3nJ/bit and 41 mW respectively.

Multichannel Ultrasonic Data Communications in Air Using Range-Dependent Modulation Schemes.

There are several well-developed technologies of wireless communication such as radio frequency (RF) and infrared (IR), but ultrasonic methods can be a good alternative in some situations. A multichannel airborne ultrasonic data communication system is described in this paper. ON-OFF keying (OOK) and binary phase-shift keying (BPSK) modulation schemes were implemented successfully in the system by using a pair of commercially available capacitive ultrasonic transducers in a relatively low multipath indoor laboratory environment. Six channels were used from 50 to 110 kHz with a channel spacing of 12 kHz, allowing multiple 8-bit data packets to be transmitted simultaneously. The system data transfer rate achieved was up to 60 kb/s and ultrasonic wireless synchronization was implemented instead of using a hard-wired link. A model developed in the work could accurately predict ultrasonic signals through the air channels. Signal root mean square (rms) values and system bit error rates (BERs) were analyzed over different distances. Error-free decoding was achieved over ranges up to 5 m using a multichannel OOK modulation scheme. To obtain the highest data transfer rate and the longest error-free transmission distance, a range-dependent multichannel scheme with variable data rates, channel frequencies, and different modulation schemes, was also studied in the work. Within 2 m, error-free transmission was achieved using a five-channel OOK with a data rate of 63 kb/s. Between 2 and 5 m, six-channel OOK with 60 kb/s data transfer rate was error free. Beyond 5 m, the error-free transmission range could be extended up to 10 m using three-channel BPSK with a reduced data rate of 30 kb/s. The situation when two transducers were misaligned using three-channel OOK and BPSK schemes was also investigated in the work. It was concluded that error-free transmission could still be achieved with a lateral displacement of less than 7% and oblique angles of less than 7°, and three-channel BPSK proved to be more robust than three-channel OOK with transducer misalignment.

A Fast Blind Detection Algorithm for Outdoor Visible Light Communications

In this paper, we consider an outdoor visible light communication system, in which on-off keying (OOK) modulation is utilized through an atmospheric turbulence-induced slow-fading channel. A new fast blind detection algorithm is proposed by following the generalized likelihood ratio test (GLRT) principle. In addition, a block coding scheme is presented to solve the unique identification issue and, thus, the error floor problem.

2 Gbit/s data transmission from an unfiltered laser-based phosphor-converted white lighting communication system.

We demonstrate data transmission of unfiltered white light generated by direct modulation of a blue gallium nitride (GaN) laser diode (LD) exciting YAG:Ce phosphors. 1.1 GHz of modulation bandwidth was measured without a limitation from the slow 3.8 MHz phosphor response. A high data transmission rate of 2 Gbit/s was achieved without an optical blue-filter using a non-return-to-zero on-off keying (NRZ-OOK) modulation scheme. The measured bit error rate (BER) of 3.50 × 10(-3) was less than the forward error correction (FEC) limit of 3.8 × 10(-3). The generated white light exhibits CIE 1931 chromaticity coordinates of (0.3628, 0.4310) with a color rendering index (CRI) of 58 and a correlated color temperature (CCT) of 4740 K when the LD was operated at 300 mA. The demonstrated laser-based lighting system can be used simultaneously for indoor broadband access and illumination applications with good color stability.

Non-reciprocity compensation correction and antenna selection for optical large MIMO system

This paper exploits an optical large multiple input multiple output (MIMO) system. We first establish the non-reciprocity compensation correction factor to solve the channel non-reciprocity problem. Then we propose an antenna selection algorithm with the goal of realizing maximum energy efficiency (EE) when satisfying the outage EE. The simulation results prove that this non-reciprocity compensation correction factor can compensate beam energy attenuation gap and spatial correlation gap between uplink and downlink effectively, and this antenna selection algorithm can economize the number of transmit antennas and achieve high EE performance. Finally, we apply direct current- biased optical orthogonal frequency division multiplexing (DCO-OFDM) modulation in our system and prove that it can improve the bit error rate (BER) compared with on-off keying (OOK) modulation, so the DCO-OFDM modulation can resist atmospheric turbulence effectively.

Low-voltage high-speed coupling modulation in silicon racetrack ring resonators.

We demonstrate a low-voltage high-speed modulator based on a silicon racetrack resonator with a tunable Mach-Zehnder interferometer coupler. Both static measurement and dynamic modulation experiment are carried out. The 3-dB electro-optic bandwidth is measured to be >30 GHz beyond the limit by the cavity photon lifetime. A 32 Gb/s on-off keying (OOK) modulation is realized under a peak-to-peak drive voltage as low as 0.4 V, and a 28 Gb/s binary phase-shift-keying (BPSK) modulation is realized with a drive voltage of 3 V. The low drive voltages results in low energy consumptions of ~13.3 fJ/bit and ~1.2 pJ/bit for OOK and BPSK modulations, respectively.

A Single-Chip Full-Duplex High Speed Transceiver for Multi-Site Stimulating and Recording Neural Implants.

We present a novel, fully-integrated, low-power full-duplex transceiver (FDT) to support high-density and bidirectional neural interfacing applications (high-channel count stimulating and recording) with asymmetric data rates: higher rates are required for recording (uplink signals) than stimulation (downlink signals). The transmitter (TX) and receiver (RX) share a single antenna to reduce implant size and complexity. The TX uses impulse radio ultra-wide band (IR-UWB) based on an edge combining approach, and the RX uses a novel 2.4-GHz on-off keying (OOK) receiver. Proper isolation (>20 dB) between the TX and RX path is implemented 1) by shaping the transmitted pulses to fall within the unregulated UWB spectrum (3.1-7 GHz), and 2) by space-efficient filtering (avoiding a circulator or diplexer) of the downlink OOK spectrum in the RX low-noise amplifier. The UWB 3.1-7 GHz transmitter can use either OOK or binary phase shift keying (BPSK) modulation schemes. The proposed FDT provides dual band 500-Mbps TX uplink data rate and 100 Mbps RX downlink data rate, and it is fully integrated into standard TSMC 0.18- μm CMOS within a total size of 0.8 mm(2). The total measured power consumption is 10.4 mW in full duplex mode (5 mW at 100 Mbps for RX, and 5.4 mW at 500 Mbps or 10.8 pJ/bit for TX). Additionally, a 3-coil inductive link along with on-chip power management circuits allows to powering up the implantable transceiver wirelessly by delivering 25 mW extracted from a 13.56-MHz carrier signal, at a total efficiency of 41.6%.

LMMSE SIMO Receiver for Short-Range Non-Line-of-Sight Scattering Communication

We propose linear minimum mean square error (LMMSE) receivers for optical wireless scattering communications with single transmitter and multiple receivers, namely the single-input multiple-output (SIMO) system, where the received signals exhibit the characteristics of discrete photons. We first propose an LMMSE receiver scheme based on photon-counting detection, and then generalize to other type of receivers with amplification gains such as photomultiplier tube (PMT) and avalanche photodetector (APD). The proposed LMMSE receiver is designed for both on-off key (OOK) modulation and pulse-position modulation (PPM), and estimated bit mean square error performance is analyzed in detail. Simulation results are provided to show the bit estimation performance of the proposed LMMSE receivers. It is concluded that OOK incurs larger estimation error at smaller required bandwidth, while $M$ -PPM with $M > 4$ leads to smaller estimation error with more bandwidth requirements.

On-Chip Polarization Controlled Mode Converter With Capability of WDM Operation

An on-chip polarization controlled mode converter compatible with wavelength division multiplexing (WDM) operation is proposed and experimentally demonstrated. The proposed chip consists of a polarization diversity structure and microring resonator-based mode converter. By selecting either horizontal or vertical linear polarization at input single-mode fiber, the input signals can be either converted to LP11 mode or maintained LP01 mode in output few-mode fiber over the C-band. For demonstration, four WDM channels with 40-Gb/s ON-OFF-keying modulation are successfully processed, with an average power penalties of 1.8 and 2.8 dB for two orthogonal linear polarization inputs, respectively. The proposed circuit is promising to process future multidimensional multiplexing signal.

56 Gb/s Germanium Waveguide Electro-Absorption Modulator

We report a Germanium waveguide electro-absorption modulator with electro-optic bandwidth substantially beyond 50 GHz. The device is implemented in a fully integrated Si photonics platform on 200 mm silicon-on-insulator wafers with 220 nm top Si thickness. Wide open eye diagrams are demonstrated at 1610 nm operation wavelength for nonreturn-to-zero on-off keying (NRZ-OOK) modulation at data rates as high as 56 Gb/s. Dynamic extinction ratios up to 3.3 dB are obtained by applying drive voltages of 2 V peak-to-peak, along with an optical insertion loss below 5.5 dB. The device has a low junction capacitance of just 12.8 fF, resulting in 12.8 fJ/bit of dynamic and ∼1.2 mW of static power consumption in typical operating conditions. Wafer-scale performance data are presented and confirm the manufacturability of the device. The demonstrated modulator shows great potential for realizing high-density and low-power silicon photonic transceivers targeting short-reach optical interconnects at serial data rates of 56 Gb/s and beyond.

Cost-Effective Direct-Detection All-Optical OOK-OFDM System With Analysis of Modulator Bandwidth and Driving Power

Optical orthogonal frequency-division multiplexing (OFDM) with advanced modulation format [e.g., quadrature amplitude modulation (QAM) and quadrature phase-shift keying (QPSK)] provides many transmission advantages. As the OFDM data rate is limited by the electronic digital-to-analog (DAC) and analog-to-digital (ADC) integrated circuits, an all-optical technique (i.e., all-optical OFDM) is used to construct an OFDM symbol; hence, it can provide a significant improvement in transmission capacity. In this work, we propose and demonstrate a cost-effective 275-Gb/s direct-detection all-optical OFDM system for access or data center networks. As all wavelength channels (11 wavelengths in the experiment) are produced by one laser source, only the temperature control of one master laser is enough. In addition, each wavelength channel in the all-optical OFDM signal is encoded using on-off keying (OOK) modulation format; the traditional generation and detection circuits used in the transmitter (Tx) and receiver (Rx) of the present passive optical network can still be used. We also numerically analyze the requirements of the opt-comb-MOD (modulator used to generate the optical comb source) and the data-MOD (modulator used to generate the OOK data) in the system.