Temat: phase noise - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Blind frequency offset estimation for overlap PCC-OFDM systems in presence of phase noise
Autorzy:: Shentu, J.
Armstrong, J.
Tematy:: OFDM
frequency offset
estimation
phase noise
overlap PCC-OFDM; Pokaż więcej
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Powiązania:: https://bibliotekanauki.pl/articles/307668.pdf Link otwiera się w nowym oknie
Opis:: This paper presents a technique for frequency offset estimation for polynomial cancellation coded orthogonal frequency division multiplexing with symbols overlapped in the time domain (overlap PCC-OFDM) in the presence of phase noise. The frequency offset estimator is designed based on the subcarrier pair imbalance (SPI) caused by frequency offset. The estimation is performed in the frequency domain at the output of the receiver discrete Fourier transform (DFT). No training symbols or pilot tones are required. Simulations show that this estimator is an approximately linear function of frequency offset. Phase noise does not significantly affect the variance performance of the estimator.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Active Inductor with Feedback Resistor Based Voltage Controlled Oscillator Design for Wireless Applications
Autorzy:: Faruqe, Omar
Amin, Md. Tawfiq
Tematy:: VCO
active inductor
inductance
quality factor
phase noise
figure-of-merit; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/226124.pdf Link otwiera się w nowym oknie
Opis:: This paper presents active inductor based VCO design for wireless applications based on analysis of active inductor models (Weng-Kuo Cascode active inductor & Liang Regular Cascode active inductor) with feedback resistor technique. Embedment of feedback resistor results in the increment of inductance as well as the quality factor whereas the values are 125.6@2.4GHz (Liang) and 98.7@3.4GHz (Weng- Kuo). The Weng-Kuo active inductor based VCO shows a tuning frequency of 1.765GHz ~2.430GHz (31.7%), while consuming a power of 2.60 mW and phase noise of -84.15 dBc/Hz@1MHz offset. On the other hand, Liang active inductor based VCO shows a frequency range of 1.897GHz ~2.522GHz (28.28%), while consuming a power of 1.40 mW and phase noise of -80.79 dBc/Hz@1MHz offset. Comparing Figure-of-Merit (FoM), power consumption, output power and stability in performance, designed active inductor based VCOs outperform with the state-of-the-art.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: A new optical frequency transfer method via fibre based on active phase noise compensation with single acousto-optic modulator
Autorzy:: Wang, Guoyong
Yao, Yuanbo
Yan, Tao
Bian, Lang
Meng, Yansong
Tematy:: acousto-optic modulator
optical frequency transfer over fibre
phase noise compensation
relative frequency stability; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/221592.pdf Link otwiera się w nowym oknie
Opis:: In this paper, we propose and experimentally demonstrate a new method for optical frequency transfer over fibre. Instead of dual acousto-optic modulators (AOMs) as adopted in the traditional fibre phase noise compensation setup, here an active fibre phase noise compensation scheme with a single acousto-optic modulator (AOM) is used. The configuration simplifies the equipment of the user end while maintaining a high-performance optical frequency transfer stability. We demonstrate an actively stabilized coherent transfer at an optical frequency of 193.55THz over 10-km spooled fibre, obtaining a relative frequency stability (Allan deviation) of 3.84 x 10^-16/1 s and 4.08 x 10^-18/10⁴ s, which is improved by about 2~3 orders of magnitude in comparison with the one without any phase noise compensation that achieves a relative frequency stability of 1.81 x 10^-14/1 s and 2.48 x 10^-15/10⁴ s.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Testing Time and Frequency Fiber-Optic Link Transfer by Hardware Emulation of Acoustic-Band Optical Noise
Autorzy:: Lipiński, M.
Krehlik, P.
Śliwczyński, Ł.
Buczek, Ł.
Kołodziej, J.
Tematy:: Time and Frequency fiber-optic transfer
phase noise in optical fiber
timing jitter
fiber-optic transmission; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/221890.pdf Link otwiera się w nowym oknie
Opis:: The low-frequency optical-signal phase noise induced by mechanical vibration of the base occurs in field-deployed fibers. Typical telecommunication data transfer is insensitive to this type of noise but the phenomenon may influence links dedicated to precise Time and Frequency (T&F) fiber-optic transfer that exploit the idea of stabilization of phase or propagation delay of the link. To measure effectiveness of suppression of acoustic noise in such a link, a dedicated measurement setup is necessary. The setup should enable to introduce a low-frequency phase corruption to the optical signal in a controllable way. In the paper, a concept of a setup in which the mechanically induced acoustic-band optical signal phase corruption is described and its own features and measured parameters are presented. Next, the experimental measurement results of the T&F transfer TFTS-2 system’s immunity as a function of the fibre-optic length vs. the acoustic-band noise are presented. Then, the dependency of the system immunity on the location of a noise source along the link is also pointed out.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: A concept of a passive radar with quadrature microwave phase discriminators
Autorzy:: Rutkowski, A. K.
Tematy:: passive radar
instantaneous frequency measurement
IFM
microwave phase discriminator
phase of noise signal; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/221600.pdf Link otwiera się w nowym oknie
Opis:: Passive radar does not have its own emitter. It uses so-called signals of opportunity emitted by non-cooperative illuminators. During the detection of reflected signals, a direct signal from a non-cooperative emitter is used as the reference signal. Detection of electromagnetic echoes is, in present day radars, performed by finding the maximum of the cross ambiguity function. This function is based on the multiplication of the received signal and the reference signal. Detection of echoes by means of a quadrature microwave phase discriminator QMPD was proposed in the work as an alternative solution for ambiguity function evaluation. This discriminator carries out vectorial summing of the received and the reference signals. The summing operations in QMPD are carried out with the aid of microwave elements and without the use of expensive digital signal processors. Definitions of the phase and phase difference of the so-called simple signals and noise signals were described. A proposal of a passive radar equipped with several independent quadrature microwave phase discriminators was presented. Ideas of algorithms of object detection and of the distance-to-object estimation designed for this radar have been also sketched.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Comparative Analysis of the Efficiency of Detecting Some Amplitude-Phase Modulated Signals in Wireless Communication Systems
Autorzy:: Bondariev, Andriy P.
Horbatyi, Ivan V.
Maksymiv, Ivan P.
Altunin, Sergiy I.
Tematy:: 8-QAM
8-AMMC
signal-to-noise ratio
noise immunity
phase detector
phase locked loop; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/227333.pdf Link otwiera się w nowym oknie
Opis:: This article presents the results of the research of noiseimmunity of wireless communication systems using signals that are formed on the basis of eight-position quadrature-amplitude modulation (8-QAM) and eight-position amplitude modulation of many components (8-AMMC). The research was conducted using simulation of a wireless communication system, built using a detector, implemented on the basis of a phase locked loop. The influence of phase locked loop parameters on the detection quality of these signals in the condition of the interference in the communication channel was researched, and a comparative analysis of the noise immunity of wireless communication systems using these signals was carried out.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Direct characterisation of AM-to-PM phenomena in fast Si and InGaAs photodiodes
Autorzy:: Budzyn, Grzegorz
Barański, Jędrzej
Tematy:: photodetector
phase
noise
laser
nonlinearities; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Powiązania:: https://bibliotekanauki.pl/articles/59112915.pdf Link otwiera się w nowym oknie
Opis:: The direct measurement method of AM-to-PM phenomena in fast silicon and InGaAs photodiodes is described. The setup is simple, relatively inexpensive and allows fast and precise measurements not only in a laboratory environment. During sample tests, the authors have found that the influence of bias voltage on the phase shift of an optical signal conversion is significant. The reported effect together with the influence of modulation depth on phase shift (AM-to-PM conversion) has a negative impact on an optical signal reception especially in coherent applications. The authors show that, with our proposed setups, it is possible to find optimal bias voltage and optimal optical power in order to reduce electrical phase noise of the photodetector.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Mathematical Modelling of Sound Radiation from a T Junction of City Roads in Windy Conditions
Autorzy:: Piddubniak, O.
Piddubniak, N.
Tematy:: T junction of city roads
traffic noise propagation
stationary phase method
acoustic pressure
power flow density; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/176734.pdf Link otwiera się w nowym oknie
Opis:: The sound radiation from vehicles travelling on the city roads with T junction was considered. The wind effect on acoustic field was taken into account. The solution of this problem was found with the help of the integral Fourier transforms and stationary phase method as the superposition of solutions for the cases of vehicles moving along the straight roads and roads with right-angle bend. As an example, the numerical analysis of traffic noise characteristics was carried out for the T junction city road on one of streets in the town of Łódź (Poland).
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Performance Enhancement of Coherent Optical OFDM System Using LMS Algorithm
Autorzy:: Bharti, Manisha
Tematy:: coherent optical-orthogonal frequency division multiplexing (CO-OFDM)
common phase error
east means quare (LMS)
chase noise; Pokaż więcej
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Powiązania:: https://bibliotekanauki.pl/articles/308124.pdf Link otwiera się w nowym oknie
Opis:: Instability of the local oscillator causes phase noise – a phenomenon that is a disadvantage and is considered to be a major obstacle in the functioning of coherent optical orthogonal frequency division multiplexing (CO-OFDM) systems. An attempt has been made in this paper to reduce the eﬀects of common phase errors generated by phase noise. In this paper, a least mean square (LMS) based algorithm is proposed for estimation of phase noise. Using this proposed algorithm, the major problem of phase ambiguity caused by cycle slip is avoided and the bit error rate is greatly improved. Further, there is no requirement for modifying the frame structure of OFDM using this algorithm. A CO-OFDM system with the 8-PSK technique is used to implement the algorithm concerned. Furthermore, the algorithm, using the 8-PSK modulation technique, is analyzed and compared with the existing QPSK technique and with other algorithms. The investigations reveal that 8-PSK outperforms existing LMS algorithms using other techniques and signiﬁcantly reduces the bit error rate.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Three dimensional optical CDMA framework with direct detection technique
Autorzy:: Panda, Satyasen
Tematy:: Cross correlation (CC)
Multiple access interference (MAI)
Phase induced intensity noise (PIIN)
Spectral amplitude coding optical code division multiple access (SAC-OCDMA)
Three dimensional modified quadratic congruence/prime hop code (3-D MQC/PHC)
Three dimensional optical code division multiple access (3-D OCDMA); Pokaż więcej
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Powiązania:: https://bibliotekanauki.pl/articles/1178377.pdf Link otwiera się w nowym oknie
Opis:: In this paper, a three-dimensional (3-D) wavelength/time/space code is developed for optical code division multiple access (OCDMA) networks with direct detection technique in the receiver side. The 3-D codes are developed by mixing two-dimensional modified quadratic congruence (MQC) code and one-dimensional prime hop code (PHC) code. The encoders and decoders are constructed using fiber Bragg gratings and delay lines to minimize the bit error rate (BER). The performance analysis of the 3-D OCDMA system is based on measurement of signal to noise ratio (SNR), BER, received power and eye diagram for different numbers of simultaneous users. Also, in the analysis, various types of noises and multiple access interference (MAI) effects are considered. The received optical power is also measured at various levels of BER to analyze the effect of attenuation.
Dostawca treści:: Biblioteka Nauki

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