scholarly journals Influence of the radio signals frequency band on their spatial selection in communication channels

2021 ◽  
Vol 279 ◽  
pp. 02002
Author(s):  
Alexander Okorochkov ◽  
Nadezda Dmitrienko
Keyword(s):  
Frequency Band ◽  
Signal To Noise Ratio ◽  
Radio Channel ◽  
Signal Transmission ◽  
Total Field ◽  
Sharp Drop ◽  
Single Carrier ◽  
Channel Bandwidth ◽  
Radio Signals ◽  
Reception Area

This article deals with the dependence of the signal-to-noise ratio (S/N) on the frequency band of a radio channel when transmitting three different radio signals over it based on a mathematical model. Signals are transmitted on a single carrier frequency, in one direction and occupy the entire channel frequency band, which varied from 0 to 30 GHz. A threeelement sparse antenna array (SAA) is used for signal transmission. Each signal is emitted by all three SAA elements with certain phase shifts. In the reception area, such a structure of the total field is formed, at which the maxima of all transmitted signals are spatially spaced. This allows each signal to be received on a separate antenna. Studies have shown that the S/N ratio for different signals depends differently on the channel bandwidth. For a signal emitted by all SAA antennas in phase, the S/N ratio is practically independent of the bandwidth and is about 70 dB. For the two remaining phased signals the S/N ratio varies equally over the entire range of the channel frequency band values and is characterized by a sharp drop from 62 to 8 dB.

scholarly journals Reliable Positioning and mmWave Communication via Multi-Point Connectivity

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 4001 ◽  
Author(s):  
Dileep Kumar ◽  
Jani Saloranta ◽  
Jarkko Kaleva ◽  
Giuseppe Destino ◽  
Antti Tölli
Keyword(s):  
Millimeter Wave ◽  
Frequency Band ◽  
Mobile Technology ◽  
Radio Channel ◽  
Signal Transmission ◽  
High Data Rate ◽  
Line Of Sight ◽  
Numerical Examples ◽  
High Data ◽  
Communication Reliability

One of the key elements of future 5G and beyond mobile technology is millimeter-wave (mmWave) communications, which is targeted to extreme high-data rate services. Furthermore, combining the possibility of a wideband signal transmission with the capability of pencil-beamforming, mmWave technology is key for accurate cellular-based positioning. However, it is also well-known that at the mmWave frequency band the radio channel is very sensitive to line-of-sight blockages giving rise to unstable connectivity and inefficient communication. In this paper, we tackle the blockage problem and propose a solution to increase the communication reliability by means of a coordinated multi-point reception. We also investigate the advantage of this solution in terms of positioning quality. More specifically, we describe a robust hybrid analog–digital receive beamforming strategy to combat the unavailability of dominant links. Numerical examples are provided to validate the efficiency of our proposed method.

scholarly journals A 1.5D Spectral Kurtosis-Guided TQWT Method and Its Application in Bearing Fault Detection

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Xiong Zhang ◽  
Ming Zhang ◽  
Shuting Wan ◽  
Rujiang Hao ◽  
Yuling He ◽  
...  
Keyword(s):  
Frequency Band ◽  
Signal To Noise Ratio ◽  
Signal Transmission ◽  
Low Frequency ◽  
Signal Frequency ◽  
Bearing Fault ◽  
Spectral Kurtosis ◽  
Fault State ◽  
Periodic Impulse ◽  
Fault Characteristic

Bearings are the key parts of rotating machinery, and their operation status is related to the operation safety of the whole equipment. Vibration signals often contain periodic impulse components which can reflect the fault state of bearings. However, due to the interference of signal transmission path and the influence of operating environment noise, the periodic impulse components in the signal are often submerged by the nonperiodic transient impulse components, modulation harmonic components, and noise components. Therefore, the core problem of bearing fault diagnosis theory is used to accurately extract the frequency band of bearing fault state information and suppress the frequency band of interference information. In this paper, the signal is processed by the tunable Q-factor wavelet transform (TQWT), the midfrequency band of the signal is tightly divided by selecting different Q-values, and the 1.5D spectral kurtosis defined in frequency domain is used to select the optimal subband. Simulated analysis shows that this method can avoid low-frequency harmonic interference, nonperiodic transient impulse components, and strong noise components in the time domain. Therefore, it can effectively realize the selection of the subbands of periodic impulse components and effectively extract fault feature information. Through experimental signal analysis, TQWT has good sparsity decomposition characteristics and can reasonably divide the signal frequency band, so as to separate the useful fault characteristic frequency band and interference frequency band. At the same time, compared with the kurtosis index, 1.5D spectral kurtosis has better robustness and resolution for low signal-to-noise ratio signals, which can achieve the purpose of fault characteristic band extraction.

scholarly journals Imbalanced post- and extrasynaptic SHANK2A functions during development affect social behavior in SHANK2-mediated neuropsychiatric disorders

2021 ◽  
Author(s):  
Ahmed Eltokhi ◽  
Miguel A. Gonzalez-Lozano ◽  
Lars-Lennart Oettl ◽  
Andrey Rozov ◽  
Claudia Pitzer ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Social Interaction ◽  
Social Behavior ◽  
Ampa Receptors ◽  
Signal To Noise Ratio ◽  
Signal Transmission ◽  
Neuropsychiatric Disorders ◽  
Autism Spectrum ◽  
Strong Impact ◽  
Odor Processing

AbstractMutations in SHANK genes play an undisputed role in neuropsychiatric disorders. Until now, research has focused on the postsynaptic function of SHANKs, and prominent postsynaptic alterations in glutamatergic signal transmission have been reported in Shank KO mouse models. Recent studies have also suggested a possible presynaptic function of SHANK proteins, but these remain poorly defined. In this study, we examined how SHANK2 can mediate electrophysiological, molecular, and behavioral effects by conditionally overexpressing either wild-type SHANK2A or the extrasynaptic SHANK2A(R462X) variant. SHANK2A overexpression affected pre- and postsynaptic targets and revealed a reversible, development-dependent autism spectrum disorder-like behavior. SHANK2A also mediated redistribution of Ca2+-permeable AMPA receptors between apical and basal hippocampal CA1 dendrites, leading to impaired synaptic plasticity in the basal dendrites. Moreover, SHANK2A overexpression reduced social interaction and increased the excitatory noise in the olfactory cortex during odor processing. In contrast, overexpression of the extrasynaptic SHANK2A(R462X) variant did not impair hippocampal synaptic plasticity, but still altered the expression of presynaptic/axonal signaling proteins. We also observed an attention-deficit/hyperactivity-like behavior and improved social interaction along with enhanced signal-to-noise ratio in cortical odor processing. Our results suggest that the disruption of pre- and postsynaptic SHANK2 functions caused by SHANK2 mutations has a strong impact on social behavior. These findings indicate that pre- and postsynaptic SHANK2 actions cooperate for normal neuronal function, and that an imbalance between these functions may lead to different neuropsychiatric disorders.

scholarly journals Optimal nonlinear filtering of M-PSK signals against a background of harmonic interference with a random initial phase

2021 ◽  
Vol 9 (6) ◽  
pp. 46-56
Author(s):  
G. V. Kulikov ◽  
Trung Tien Do ◽  
E. V. Samokhina
Keyword(s):  
Initial Phase ◽  
Nonlinear Filtering ◽  
Noise Immunity ◽  
Signal To Noise Ratio ◽  
Radio Channel ◽  
Complete Suppression ◽  
Two Phase ◽  
Probability Of Error ◽  
Useful Signal ◽  
Optimal Nonlinear Filtering

Objectives. The widespread use of radio data transmission systems using signals with multiposition phase shift keying (MPSK) is due to their high noise immunity and the simplicity of constructing the transmitting and receiving parts of the equipment. The conducted studies have shown that the presence of non-fluctuation interference, in particular, harmonic interference, in the radio channel significantly reduces the noise immunity of receiving discrete information. The energy loss in this case, depending on the interference intensity, can range from fractions of dB to 10 db or more. Therefore, interference suppression is an important task for such radio systems. The aim of the work is to synthesize and analyze an algorithm for optimal nonlinear filtering of MPSK signals against a background of harmonic interference with a random initial phase.Methods. The provisions of the theory of optimal nonlinear signal filtering and methods of statistical radio engineering are used.Results. The synthesis and analysis of the algorithm of optimal nonlinear filtering of MPSK signals against the background of harmonic interference with a random initial phase are carried out. The synthesized receiver contains a discrete symbol evaluation unit, two phase-locked frequency circuits of reference generators that form evaluation copies of the signal and interference, and cross-links between them. Analytical expressions are obtained that allow calculating the dependences of the bit error probability on the signal-to-noise ratio and the interference intensity µ. It is established that uncompensated fluctuations of the initial phase of the useful signal have a greater effect on the receiver noise immunity than similar fluctuations of the phase of harmonic interference, especially with low positional signals.Conclusions. Comparison of the obtained results with the results obtained in the case when there are no harmonic interference compensation circuits shows that the use of the obtained phase filtering algorithms allows for almost complete suppression of harmonic interference. Thus, if µ = 0.5 and the probability of error is 10−2, the energy gain at M = 2 is about 2.5 dB, at M = 4 – about 6 dB, at M = 8 and M = 16 – at least 10 dB.

SAMPLE CLOCK OFFSET COMPENSATION IN THE FIFTH-GENERATION NEW RADIO UPLINK

2021 ◽  
Author(s):  
О.Г. ПОНОМАРЕВ ◽  
М. АСАФ
Keyword(s):  
Signal To Noise Ratio ◽  
Radio Channel ◽  
Estimation Method ◽  
Estimation Methods ◽  
Fifth Generation ◽  
New Radio ◽  
Shared Channel ◽  
Wide Range ◽  
Offset Compensation ◽  
Clock Offset

Рассмотрена проблема коррекции искажений OFDM-сигнала, вызванных смещением частоты дискретизации сигнала в приемном и передающем устройствах системы сотовой связи пятого поколения. Предлагаемый метод компенсации смещения частоты дискретизации основывается на прямой коррекции искажений, вносимых в передаваемый сигнал наличием смещения, и не предполагает какой-либо оценки величины смещения. Метод предназначен для коррекции сигналов в восходящем канале системы сотовой связи пятого поколения и основывается на использовании референсных сигналов, рекомендованных стандартами 3GPP. Результаты численного моделирования показали, что использование предлагаемого метода позволяет повысить эффективность передачи данных по многолучевому радиоканалу более чем на 15% в широком диапазоне значений отношения сигнал/шум. 5G-NR, CP-OFDM, synchronization, sample clock offset, PUSCH. О The paper investigates the issue of sampling clock offset ( SCO) in the fifth generation new radio systems. Due to the imperfect SCO estimation methods, the correction methods relying on the SCO estimation are not perfect, so the proposed method directly corrects the effect of SCO without using any kind of estimation method. Our method is designed to correct the signals in the physical uplink shared channel (PUSCH). The method uses reference signals as recommended by the 3rd generation partnership project (3GPP) standards. The results of the numerical simulation show that the use of the proposed method increases the efficiency of data transmission over the multipath radio channel by more than 15% in a wide range of signal-to-noise ratio values.

A Novel Delay-Based GFSK Demodulator in 65 nm CMOS for Low Power Biomedical Applications

2018 ◽  
Vol 10 (3) ◽  
pp. 21-32
Author(s):  
Meng Fu ◽  
Stan Skafidas ◽  
Iven Mareels
Keyword(s):  
Low Power ◽  
Biomedical Applications ◽  
Signal To Noise Ratio ◽  
Electronic Devices ◽  
Silicon Area ◽  
Novel Structure ◽  
Channel Bandwidth ◽  
Shift Keying ◽  
Mics Band ◽  
Demodulation Method

This article describes how, in recent years, with the development of microelectronics, implantable electronic devices have been playing a significant role in modem medicine. Examples of such electronic implant devices are, for instance, retinal prosthesis and brain implants. It brings great challenges in low power radio frequency (RF) and analog designs. This article presents a low power Gaussian frequency shift keying (GFSK) demodulator designed for Medical Implant Communications Service (MICS) band Receiver. This demodulator utilizes a novel structure that a wide IF range can be handled and presents the smallest Δf/f ratio in any published GFSK demodulators. In theory the demodulation method can be applied to any RF frequency. The demodulator draws 550uA from a 1 V power supply. A maximum data rate of 400 Kbits/s can be achieved within the 300 KHz channel bandwidth defined by MICS. A simulated signal-to-noise ratio (SNR) of 15.2dB at AWGN channel is obtained to achieve 10-3 bit error rate (BER). This demodulator is fabricated on 65-nm CMOS and occupies 0.12mm2 silicon area.

scholarly journals Coded continuous wave meteor radar

2016 ◽  
Vol 9 (2) ◽  
pp. 829-839 ◽  
Author(s):  
Juha Vierinen ◽  
Jorge L. Chau ◽  
Nico Pfeffer ◽  
Matthias Clahsen ◽  
Gunter Stober
Keyword(s):  
Frequency Band ◽  
Peak Power ◽  
Large Scale ◽  
Pulse Compression ◽  
Continuous Wave ◽  
Signal To Noise Ratio ◽  
Radar Data ◽  
Meteor Radar ◽  
To Receive ◽  
Computation Speed

Abstract. The concept of a coded continuous wave specular meteor radar (SMR) is described. The radar uses a continuously transmitted pseudorandom phase-modulated waveform, which has several advantages compared to conventional pulsed SMRs. The coding avoids range and Doppler aliasing, which are in some cases problematic with pulsed radars. Continuous transmissions maximize pulse compression gain, allowing operation at lower peak power than a pulsed system. With continuous coding, the temporal and spectral resolution are not dependent on the transmit waveform and they can be fairly flexibly changed after performing a measurement. The low signal-to-noise ratio before pulse compression, combined with independent pseudorandom transmit waveforms, allows multiple geographically separated transmitters to be used in the same frequency band simultaneously without significantly interfering with each other. Because the same frequency band can be used by multiple transmitters, the same interferometric receiver antennas can be used to receive multiple transmitters at the same time. The principles of the signal processing are discussed, in addition to discussion of several practical ways to increase computation speed, and how to optimally detect meteor echoes. Measurements from a campaign performed with a coded continuous wave SMR are shown and compared with two standard pulsed SMR measurements. The type of meteor radar described in this paper would be suited for use in a large-scale multi-static network of meteor radar transmitters and receivers. Such a system would be useful for increasing the number of meteor detections to obtain improved meteor radar data products.

scholarly journals Uplink Transmit Power Control for Single-Carrier Grouped FDMA with Iterative Multiuser Detection

2019 ◽  
Vol 10 (1) ◽  
pp. 119
Author(s):  
Yong-Sang Cho ◽  
Yun-Seong Kang ◽  
Moonsik Min
Keyword(s):  
Power Control ◽  
Multiuser Detection ◽  
Spectral Efficiency ◽  
Control Method ◽  
Signal To Noise Ratio ◽  
Transmit Power ◽  
Time Frequency ◽  
Evolution Simulation ◽  
Single Carrier ◽  
Iterative Multiuser Detection

We consider an uplink power allocation scheme for single-carrier frequency-division multiple access (FDMA) with iterative multiuser detection, called single-carrier grouped FDMA (SC-GFDMA). SC-GFDMA is a non-orthogonal scheme in which several users share a single time-frequency resource. Hence, the uplink signal of a user can be regarded as both a signal and a source of interference. The signal power of each user should be sufficiently high to ensure reliable signal detection and sufficiently low to suppress inter-user interference. That is, the transmit power of each user should be adjusted appropriately to achieve high spectral efficiency. In this context, a power control method for an uplink SC-GFDMA system is proposed by analyzing the signal-to-interference-plus-noise ratios of users sharing each time-frequency resource. In particular, the uplink spectral efficiency is improved by limiting the transmit power of each user according to a criterion derived using a semi-analytic method called signal-to-noise ratio-variance density evolution. Simulation results demonstrate that the proposed method can significantly increase the spectral efficiency of the system, even with a considerably reduced total transmit power.

SIMULATOR ERROR STREAM IN THE DATA CHANNEL WHEN RECEIVING BINARY DIGITAL RADIO SIGNALS

2019 ◽  
Vol 12 (2) ◽  
pp. 59-65
Author(s):  
В. Лавлинский ◽  
V. Lavlinskiy ◽  
Юрий Громов ◽  
Yuriy Gromov ◽  
Ирина Дидрих ◽  
...  
Keyword(s):  
Data Transmission ◽  
Data Exchange ◽  
Radio Channel ◽  
Flow Simulation ◽  
Phenomenological Approach ◽  
Digital Signals ◽  
Digital Radio ◽  
Data Channel ◽  
Radio Signals ◽  
Flow Simulator

Based on the phenomenological approach, a simulator of the error flow in the sequence of data transmitted over the radio channel is developed. The proposed version of the simulator takes into account the features of coherent and incoherent reception of the most common binary digital signals with relative phase and frequency manipulation. Within the framework of data transmission modeling, the adequacy of the results and the possibility of using the considered method of error flow simulation are fully confirmed. The developed error flow simulator allows to evaluate the potential qualitative characteristics of data transmission and the effectiveness of data exchange protocols using radio channels. At the same time, the simulator implements the connection of the structure and intensity of the generated error flow with the technical characteristics of the data transmission means used and the conditions of communication.

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