- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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OFDM tolerance to additive white Gaussian and laser phase noises in optical heterodyning systems accompanied by the feasible pilot-assisted equalization
摘要： It is well known that the performance of orthogonal frequency division multiplexing (OFDM) is limited by phase noise, which depends on the laser linewidths for coherent-detection radio over fiber (RoF) systems. In this manuscript, we present numerical and theoretical results to analyze the combined effects of phase and additive white Gaussian noises in the performance of RoF-OFDM schemes with the feasible pilot-based channel corrector. This phase-noise compensator is adopted due to its effectiveness as well as simplicity. It is shown that as the subcarrier modulation format increases, the required radio frequency linewidth for overcoming the FEC limit decreases by a factor of 10 times. Also, there is a signal–noise ratio penalty of 7 dB. Furthermore, it is demonstrated that the bit error rate enhances as the product of the laser linewidths and OFDM symbol period decreases because the pilot-assisted equalization method acts as a high-pass filter for phase noise. We finally discovered that the intermediate-frequency (IF) carrier suppression is not mandatory; the system performance is not affected by selecting properly the carrier–signal ratio and IF. To confirm the previous observation, a novel way to measure phase noise in RoF-OFDM signals accompanied by the IF carrier is proposed. The mean integral phase noise comes from the adaptation of the root mean square phase deviation of the single-carrier systems. This work serves as a guideline for the study and design of OFDM-based RoF schemes susceptible to direct and coherent detections.
关键词： Laser phase noise,Additive white Gaussian noise,Intermediate frequency suppression,Orthogonal frequency division multiplexing,Radio over fiber systems
更新于2025-09-19 17:13:59
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[IEEE 2019 Workshop on Recent Advances in Photonics (WRAP) - Guwahati, India (2019.12.13-2019.12.14)] 2019 Workshop on Recent Advances in Photonics (WRAP) - All-Dielectric Metasurfaces for Reflection and Transmission-Mode Color Filter Arrays
摘要： A major drawback of frequency modulated continuous-wave (FMCW) radar systems is the permanent leakage from the transmit into the receive path. Besides leakage within the radar device itself, signal reflections from a fixed object in front of the antennas additionally introduce so-called short-range (SR) leakage. It causes a strong degradation of detection sensitivity due to the unavoidable phase noise of the transmit oscillator. In this work, we introduce an artificial on-chip target (OCT) to mitigate the SR leakage. The OCT consists of a delay line whose time delay is significantly smaller than the round-trip delay time of the SR leakage. This is motivated by the fact that in integrated circuits for automotive radar applications operating at 77 GHz delay lines in the range of only a few picoseconds can be realized with a reasonable amount of circuitry. Despite this constraint, we show that the proposed method achieves almost perfect cancelation of the SR leakage. The concept is based on the cross-correlation properties of the residual phase noise in the intermediate frequency (IF) domain. Further, the effectiveness of the proposed method is verified in an FMCW radar system simulation. It almost perfectly shows that a gain in sensitivity of approximately 6 dB is achieved, compensating for the performance degradation caused by the SR leakage. The novel leakage cancelation concept is carried out mainly in the digital domain enabling high flexibility and adaptivity.
关键词： Digital signal processing,frequency modulated continuous-wave (FMCW) radar,leakage cancelation,phase noise,reflected power canceler
更新于2025-09-19 17:13:59
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[IEEE 2020 IEEE International Conference on Consumer Electronics (ICCE) - Las Vegas, NV, USA (2020.1.4-2020.1.6)] 2020 IEEE International Conference on Consumer Electronics (ICCE) - A Novel Method to Reduce Luminance Variation Due to IR-drop in Active Matrix OLED Displays
摘要： A major drawback of frequency modulated continuous-wave (FMCW) radar systems is the permanent leakage from the transmit into the receive path. Besides leakage within the radar device itself, signal reflections from a fixed object in front of the antennas additionally introduce so-called short-range (SR) leakage. It causes a strong degradation of detection sensitivity due to the unavoidable phase noise of the transmit oscillator. In this work, we introduce an artificial on-chip target (OCT) to mitigate the SR leakage. The OCT consists of a delay line whose time delay is significantly smaller than the round-trip delay time of the SR leakage. This is motivated by the fact that in integrated circuits for automotive radar applications operating at 77 GHz delay lines in the range of only a few picoseconds can be realized with a reasonable amount of circuitry. Despite this constraint, we show that the proposed method achieves almost perfect cancelation of the SR leakage. The concept is based on the cross-correlation properties of the residual phase noise in the intermediate frequency (IF) domain. Further, the effectiveness of the proposed method is verified in an FMCW radar system simulation. It almost perfectly shows that a gain in sensitivity of approximately 6 dB is achieved, compensating for the performance degradation caused by the SR leakage. The novel leakage cancelation concept is carried out mainly in the digital domain enabling high flexibility and adaptivity.
关键词： frequency modulated continuous-wave (FMCW) radar,phase noise,leakage cancelation,Digital signal processing,reflected power canceler
更新于2025-09-19 17:13:59
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[IEEE 2019 15th International Conference on Electronics, Computer and Computation (ICECCO) - Abuja, Nigeria (2019.12.10-2019.12.12)] 2019 15th International Conference on Electronics, Computer and Computation (ICECCO) - Using Solar Photovoltaic Systems to Significantly Reduce Power Production Problems in Nigeria and Create a Greener Environment
摘要： A major drawback of frequency modulated continuous-wave (FMCW) radar systems is the permanent leakage from the transmit into the receive path. Besides leakage within the radar device itself, signal reflections from a fixed object in front of the antennas additionally introduce so-called short-range (SR) leakage. It causes a strong degradation of detection sensitivity due to the unavoidable phase noise of the transmit oscillator. In this work, we introduce an artificial on-chip target (OCT) to mitigate the SR leakage. The OCT consists of a delay line whose time delay is significantly smaller than the round-trip delay time of the SR leakage. This is motivated by the fact that in integrated circuits for automotive radar applications operating at 77 GHz delay lines in the range of only a few picoseconds can be realized with a reasonable amount of circuitry. Despite this constraint, we show that the proposed method achieves almost perfect cancelation of the SR leakage. The concept is based on the cross-correlation properties of the residual phase noise in the intermediate frequency (IF) domain. Further, the effectiveness of the proposed method is verified in an FMCW radar system simulation. It almost perfectly shows that a gain in sensitivity of approximately 6 dB is achieved, compensating for the performance degradation caused by the SR leakage. The novel leakage cancelation concept is carried out mainly in the digital domain enabling high flexibility and adaptivity.
关键词： frequency modulated continuous-wave (FMCW) radar,phase noise,leakage cancelation,Digital signal processing,reflected power canceler
更新于2025-09-19 17:13:59
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Regional-Centralized Content Dissemination for eV2X services in 5G mmWave-enabled IoVs
摘要： In this paper, we exploit an idea of coupling multiple oscillators to reduce phase noise (PN) to beyond the limit of what has been practically achievable so far in a bulk CMOS technology. We then apply it to demonstrate for the first time an RF oscillator that meets the most stringent PN requirements of cellular basestation receivers while abiding by the process technology reliability rules. The oscillator is realized in digital 65-nm CMOS as a dual-core LC-tank oscillator based on a high-swing class-C topology. It is tunable within 4.07–4.91 GHz, while drawing 39–59 mA from a 2.15 V power supply. The measured PN is ?146.7 dBc/Hz and ?163.1 dBc/Hz at 3 MHz and 20 MHz offset, respectively, from a 4.07 GHz carrier, which makes it the lowest reported normalized PN of an integrated CMOS oscillator. Straightforward expressions for PN and interconnect resistance between the cores are derived and verified against circuit simulations and measurements. Analysis and simulations show that the interconnect resistance is not critical even with a 1% mismatch between the cores. This approach can be extended to a higher number of cores and achieve an arbitrary reduction in PN at the cost of the power and area.
关键词： LC-tank,Basestation (BTS),phase noise,figure of merit (FoM),class-C oscillator,coupled oscillators
更新于2025-09-19 17:13:59
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[IEEE 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Xiamen, China (2019.12.17-2019.12.20)] 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Parametric Simulation of a??Hot-wirea??-based Gas Velocity Sensor Using Optical Fiber
摘要： A new quadrature oscillator topology is proposed, which arranges four low-Q series LC tanks in a ring structure driven by inverters operating in class-D. With a very small area of 0.007 that is comparable to conventional ring oscillators, this oscillator has 7–20 dB better phase noise FoM of 177 dB. It is widely tunable for nearly an octave from 2.66 to 4.97 GHz.
关键词： low inductor,phase noise,wide tuning,low area,quadrature oscillator,LC oscillator,ring oscillator,series LC,Class-D oscillator,nanoscale CMOS
更新于2025-09-19 17:13:59
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[IEEE 2019 Photonics North (PN) - Quebec City, QC, Canada (2019.5.21-2019.5.23)] 2019 Photonics North (PN) - Study of nonlinear optical refractive index in thin films formed by bloom gelatin and organic materials : (Indigo carmine dye and phenol red Ph indicator)
摘要： The presence of phase noise (PN) severely deteriorates the sensitivity and range of frequency-modulated continuous wave radar systems. Thus, characterization and continuous monitoring of the PN is indispensable, and its estimation is often employed directly on chip. Although many contributions investigate methods for PN estimation, almost all of them consider a continuous-wave (CW) input signal. Differently, in this paper, we aim to estimate the PN from a linear frequency modulated continuous wave (FMCW) signal. For that, we propose two methods utilizing a so-called artificial on-chip target and further digital signal processing. These methods are evaluated in real-time and are the first-known solutions to determine PN estimates during the operation of an FMCW radar transceiver. We prove our methods with both simulation and measurement results from a hardware prototype. Further, we present techniques to efficiently realize the concepts in digital hardware. Finally, we compare and trade off the proposed methods against computational complexity and performance. The novel techniques may be applied to arbitrary input frequencies and bandwidths, and do not require a reference-clock input.
关键词： Delay lines,millimeter-wave radar,phase noise (PN),(FMCW),estimation,monolithic microwave integrated circuits,frequency-modulated continuous wave
更新于2025-09-19 17:13:59
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Research on the Gain Saturation Induced Noise in an Optical Fiber Sensing System
摘要： In an optical fiber sensing time division multiplexing (TDM) system, when the optical pulse with high peak power and low repetition rates is boost amplified, it is prone to be gain saturation and pulse distortion. The paper analysed their effects on the intensity and phase noises, and the results show that the pulse distortion induced noise is mainly down-converted relative intensity noise (RIN) lines spectra caused by the gain jitter. Then the RIN lines are converted into corresponding phase noise lines by the interferometer, which finally cause false signals in the sensor system. However in the case of saturated gain and pulse distortion, the increase of noise background is insignificant. Basing on the above results, several noise suppression schemes have been proposed, which will provide guidance for the design of large-scale remote sensing systems in the future.
关键词： Pulse distortion,Gain saturation,Relative intensity noise,Phase noise,Optical fiber sensor
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - A New Method for Measuring Laser Noise Based on Non-equilibrium Fiber Optic Interference System
摘要： A new method is proposed to measure the intensity noise and phase noise of laser by using the natural drift of the fiber optic working point of the non-equilibrium interferometer.
关键词： Non-equilibrium fiber optic interferometer,Phase noise,Laser technology,Intensity noise
更新于2025-09-16 10:30:52
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[IEEE 2018 International Topical Meeting on Microwave Photonics (MWP) - Toulouse (2018.10.22-2018.10.25)] 2018 International Topical Meeting on Microwave Photonics (MWP) - Strategies for noise reduction of a dual-frequency VECSEL dedicated to cesium CPT clocks
摘要： We investigate the strategies to reduce the noise of a class-A dual-frequency vertical external cavity surface emitting laser (VECSEL) operating at Cesium clock wavelength. We focus mainly on the beatnote phase noise of the two orthogonally polarized modes emitted. Within the framework of coupled rate equations, we show that the phase noise spectrum of the beatnote is well described by considering both the phase–amplitude coupling and the thermal effects. The spearhead of this study consists in ?rst theoretically evidencing reduction strategies for the phase noise beatnote by optimizing the physical parameters of the model and then experimentally demonstrating its feasibility by using two in-phase fully–correlated beams pumping each mode separately. Possible ways to decrease the intensity noises are also identi?ed.
关键词： vertical external cavity surface emitting laser,Dual-frequency laser,intensity noise,cesium clock,phase noise
更新于2025-09-16 10:30:52