scholarly journals Impact of accelerometer based in physical layer wireless networks

2018 ◽  
Vol 7 (2.5) ◽  
pp. 15
Author(s):  
Zuhanis Mansor ◽  
Muhammad Khairulanwar bin Zulkafli
Keyword(s):  
Wireless Communication ◽  
Landscape Position ◽  
Line Of Sight ◽  
Noise Power ◽  
Signal Power ◽  
Propagation Channel ◽  
Signal To Noise ◽  
Downlink Throughput ◽  
The Impact ◽  
Non Line Of Sight

The initial deployments of antenna in the handset consist of fixed non-rotated antenna for transmitting and receiving the signal in the wireless communication scenario. However, link correlation at the UE shows very bad performance when the handset rotates in landscape position. This paper evaluates the impact of accelerometer on the downlink propagation channel of 3G smartphone for non-line-of-sight links. The performance average received signal power is studied for user equipment. Results show that the exploitation of an accelerometer provide better performance in terms of received signal power when the handset rotated from portrait to landscape position. It can be concluded that the deployment of accelerometer can be used to improve existing 3G smartphone received signal. Results also indicate that accelerometer can be used to improve downlink throughput since the signal-to-noise-power is increased by approximately 16%.

scholarly journals Analisis Performansi Multi User Detection pada Kanal NLOS untuk Sistem NOMA-VLC

2021 ◽  
Vol 9 (2) ◽  
pp. 482
Author(s):  
BIMA SURYA PRATAMA ◽  
NACHWAN MUFTI ADRIANSYAH ◽  
BRIAN PAMUKTI
Keyword(s):  
Wireless Communication ◽  
Visible Light ◽  
Interference Cancellation ◽  
Multiple Access ◽  
Data Rate ◽  
Line Of Sight ◽  
Optical Wireless Communication ◽  
Optical Wireless ◽  
Better Than ◽  
Non Line Of Sight

ABSTRAKNon-orthogonal multiple access (NOMA), mulai diteliti untuk dapat digunakan sebagai teknik multiple access yang efektif pada jaringan 5G karena teknik ini dapat menghemat bandwidth modulasi. Pada penelitian ini, NOMA diterapkan untuk sistem downlink Visible Light Communivation (VLC). Kami telah melakukan analisis performansi Multi-User Detection (MUD) pada kanal propagasi Non-Line of Sight (NLOS) dengan mempertimbangkan efek reflektor dan efek bayangan (shadowing). Kami juga mempertimbangkan teknik MUD yang digunakan pada penelitian ini yaitu Succesive Interference Cancellation (SIC). Setelah simulasi yang ekstensif, kami menemukan bahwa dengan penerapan SIC sebagai MUD pada sistem NOMA-VLC lebih baik dibandingkan dengan tanpa NOMA. Selain itu, kami juga memperoleh peningkatan data rate sebesar 72 %.Kata kunci: VLC, NOMA, NLOS, MUD, Optical Wireless Communication. ABSTRACTNon-orthogonal multiple access (NOMA), began to be studied to be used as an effective multiple access technique on 5G networks because this technique can save modulation bandwidth. In this research, NOMA is applied to the Visible Light Communivation (VLC) downlink system. We have performed a Multi-User Detection (MUD) performance analysis on Non-Line of Sight (NLOS) propagation channels by considering the reflector and shadowing effects. We also consider the MUD technique used in this study, namely Successive Interference Cancellation (SIC). After extensive simulations, we found that the application of SIC as MUD to the NOMA-VLC system is better than without NOMA. In addition, we also achieve an increase in data rate of 72%.Keywords: VLC, NOMA, NLOS, MUD, Optical Wireless Communication.

scholarly journals Low-latency time-of-flight non-line-of-sight imaging at 5 frames per second

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ji Hyun Nam ◽  
Eric Brandt ◽  
Sebastian Bauer ◽  
Xiaochun Liu ◽  
Marco Renna ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Time Of Flight ◽  
Motion Blur ◽  
Line Of Sight ◽  
Low Latency ◽  
Imaging Method ◽  
Signal To Noise ◽  
Array Detectors ◽  
Noise Ratio ◽  
Non Line Of Sight

AbstractNon-Line-Of-Sight (NLOS) imaging aims at recovering the 3D geometry of objects that are hidden from the direct line of sight. One major challenge with this technique is the weak available multibounce signal limiting scene size, capture speed, and reconstruction quality. To overcome this obstacle, we introduce a multipixel time-of-flight non-line-of-sight imaging method combining specifically designed Single Photon Avalanche Diode (SPAD) array detectors with a fast reconstruction algorithm that captures and reconstructs live low-latency videos of non-line-of-sight scenes with natural non-retroreflective objects. We develop a model of the signal-to-noise-ratio of non-line-of-sight imaging and use it to devise a method that reconstructs the scene such that signal-to-noise-ratio, motion blur, angular resolution, and depth resolution are all independent of scene depth suggesting that reconstruction of very large scenes may be possible.

scholarly journals Coherent Power Measurements with a Compact Airborne Ka-Band Precipitation Radar

2018 ◽  
Vol 35 (1) ◽  
pp. 3-20 ◽  
Author(s):  
Andrew L. Pazmany ◽  
Samuel J. Haimov
Keyword(s):  
Signal To Noise Ratio ◽  
Power Estimation ◽  
Noise Power ◽  
Signal Power ◽  
Signal To Noise ◽  
Precipitation Radar ◽  
Noise Component ◽  
Ka Band ◽  
Noise Ratio ◽  
Conventional Signal

AbstractCoherent power is an alternative to the conventional noise-subtracted power technique for measuring weather radar signal power. The inherent noise-canceling feature of coherent power eliminates the need for estimating and subtracting the noise component, which is required when performing conventional signal power estimation at low signal-to-noise ratio. The coherent power technique is particularly useful when averaging a high number of samples to improve sensitivity to weak signals. In such cases, the signal power is small compared to the noise power and the required accuracy of the estimated noise power may be difficult to achieve. This paper compares conventional signal power estimation with the coherent power measurement technique by investigating bias, standard deviation, and probability of false alarm and detection rates as a function of signal-to-noise ratio and threshold level. This comparison is performed using analytical expressions, numerical simulations, and analysis of cloud and precipitation data collected with the airborne solid-state Ka-band precipitation radar (KPR) operated by the University of Wyoming.

scholarly journals A systematic bias in fitting the surface-density profiles of interstellar filaments

2021 ◽  
Author(s):  
A P Whitworth ◽  
F D Priestley ◽  
D Arzoumanian
Keyword(s):  
Surface Density ◽  
Dust Emission ◽  
Line Of Sight ◽  
Systematic Bias ◽  
Finite Range ◽  
Signal To Noise ◽  
Density Profiles ◽  
A Value ◽  
The Impact ◽  
Scale Length

Abstract The surface-density profiles of dense filaments, in particular those traced by dust emission, appear to be well fit with Plummer profiles, i.e. Σ(b) = ΣB + ΣO{1 + [b/wO]2}[1 − p]/2. Here  ΣB is the background surface-density;  ΣB + ΣO is the surface-density on the filament spine;  b is the impact parameter of the line-of-sight relative to the filament spine;  wO is the Plummer scale-length (which for fixed p is exactly proportional to the full-width at half-maximum, $w_{{\rm O}}=\rm {\small FWHM}/2\lbrace 2^{2/[p-1]}-1\rbrace ^{1/2}$); and  p is the Plummer exponent (which reflects the slope of the surface-density profile away from the spine). In order to improve signal-to-noise it is standard practice to average the observed surface-densities along a section of the filament, or even along its whole length, before fitting the profile. We show that, if filaments do indeed have intrinsic Plummer profiles with exponent pINTRINSIC, but there is a range of wO values along the length of the filament (and secondarily a range of ΣB values), the value of the Plummer exponent, pFIT, estimated by fitting the averaged profile, may be significantly less than pINTRINSIC. The decrease, Δp = pINTRINSIC − pFIT, increases monotonically (i) with increasing pINTRINSIC; (ii) with increasing range of wO values; and (iii) if (but only if) there is a finite range of wO values, with increasing range of ΣB values. For typical filament parameters the decrease is insignificant if pINTRINSIC = 2 (0.05 ≲ Δp ≲ 0.10), but for pINTRINSIC = 3 it is larger (0.18 ≲ Δp ≲ 0.50), and for pINTRINSIC = 4 it is substantial (0.50 ≲ Δp ≲ 1.15). On its own this effect is probably insufficient to support a value of pINTRINSIC much greater than pFIT ≃ 2, but it could be important in combination with other effects.

Non-line-of-sight Error Mitigation in Wireless Communication Systems

2011 ◽  
Vol 6 (11) ◽  
Author(s):  
Chien-Sheng Chen ◽  
Ho-Nien Shou ◽  
Lih-Chang Wung ◽  
Ching-Lung Chi
Keyword(s):  
Wireless Communication ◽  
Communication Systems ◽  
Line Of Sight ◽  
Wireless Communication Systems ◽  
Error Mitigation ◽  
Non Line Of Sight
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