scholarly journals Synchronization-Free RadChat for Automotive Radar Interference Mitigation

2021 ◽  
Vol 13 (12) ◽  
pp. 6891
Author(s):  
Canan Aydogdu ◽  
Henk Wymeersch ◽  
Olof Eriksson ◽  
Hans Herbertsson ◽  
Mats Rydström
Keyword(s):  
Interference Mitigation ◽  
Time Synchronization ◽  
Use Cases ◽  
Automotive Radar ◽  
Relative Time ◽  
Short Intervals ◽  
Absolute Time ◽  
Simulation Results ◽  
The Absolute ◽  
Radar Sensing

Automotive radar interference mitigation is expected to be inherent in all future ADAS and AD vehicles. Joint radar communications is a candidate technology for removing this interference by coordinating radar sensing through communication. Coordination of radars requires strict time synchronization among vehicles, and our formerly proposed protocol (RadChat) achieves this by a precise absolute time, provided by GPS clocks of vehicles. However, interference might appear if synchronization among vehicles is lost in case GPS is spoofed, satellites are blocked over short intervals, or GPS is restarted/updated. Here we present a synchronization-free version of RadChat (Sync-free RadChat), which relies on using the relative time for radar coordination, eliminating the dependency on the absolute time provided by GPS. Simulation results obtained for various use cases show that Sync-free RadChat is able to mitigate interference without degrading the radar performance.

scholarly journals Albanian Aorist and Time Reference Points

2020 ◽  
Vol 10 (3) ◽  
pp. 115
Author(s):  
Muhamet Reçica ◽  
Naser Pajaziti
Keyword(s):  
Reference Point ◽  
Reference Points ◽  
The Other ◽  
Temporal Relations ◽  
Time Dimension ◽  
Relative Time ◽  
Absolute Time ◽  
Temporal System ◽  
The Absolute

Topics related to the structure of the temporal system of Albanian language always give opportunities for new discussions to deal with certain aspects related to various forms of this system, and one of them is the aorist, as a tense containing many semantic, temporal, aspectual, stylistic values, etc. The relationships that exist between the verbal tenses in this system within the absolute time-relative time dimension, which relate to the independent or dependent use of temporal forms against one another in different discoursing contexts, make up an interpretation-based approach to interest. Hence, the essential objective of this paper will be specifically the relations of the Albanian aorist to the other verbal forms, always observed with a time reference point, to illuminate the character of these purely temporal relations against each other under all circumstances of the actions that take place and are displayed by verbal forms in different contexts, relying on the corpus of examined materials.

scholarly journals Modified Lorentz transformations and quantum mechanics

2021 ◽  
Author(s):  
Jae-Kwang Hwang
Keyword(s):  
Wave Function ◽  
Quantum Mechanics ◽  
Euclidean Space ◽  
Coordinate System ◽  
Space Time ◽  
Lorentz Transformations ◽  
Relative Time ◽  
Absolute Time ◽  
Time Shape ◽  
The Absolute

Abstract We live in the 4-D Euclidean space. The 4th dimension is assigned as the absolute time (ct) axis and energy axis (cPt = E0) based on 4-dimensional Euclidean space. This 4th dimension can be indirectly felt through the observable relative time (ctl) and observable total energy (cPtl = E). The space-time distance is d(x1x2x3x4) = ctl. The modified Lorentz transformations are introduced by the time-matching of the absolute times in the 4-D Euclidean space. The size of x’ (or Dx’) of the moving object is expanded to the size of x = gx’ (or Dx = gDx’). These modified Lorentz transformations are approximated to the Lorentz transformations as t à tl when v/c << 1 and to the Galilean transformations as v/c is close to zero. The relative time (tl) and energy (E) are defined as the 4-dimensional distance and 4-dimensional volume, respectively. The geometrical space-time shape has the (x1,x2,x3,ct) coordinate system with the metric signature of (+ + + +) but not the (x1,x2,x3,ctl) coordinate system with the metric signature of (+ - - -). Therefore, d(x1x2x3x4)2 = (ctl)2 = (ct)2 +x2 = x12 + x22 + x32 + x42 and V(x1x2x3x4) = E = mc2 = D(ct)Dx1Dx2Dx3 from (x1,x2,x3,x4) of the geometrical space-time shape. The warped shape can be described as the wave function of the quantum mechanics. The instant force action, twin paradox and possible space travel are explained by the absolute time and wave function collapse of the modified Lorentz transformations and quantum mechanics.

scholarly journals W-band voltage-controlled oscillator design in 130 nm SiGe BiCMOS technology

2019 ◽  
Vol 30 ◽  
pp. 01006
Author(s):  
Alexander Kozhemyakin ◽  
Ivan Kravchenko
Keyword(s):  
Power Consumption ◽  
Output Power ◽  
Design Flow ◽  
Voltage Controlled Oscillator ◽  
Automotive Radar ◽  
W Band ◽  
Bicmos Technology ◽  
Sige Bicmos ◽  
Fundamental Oscillation ◽  
Simulation Results

The paper presents design flow and simulation results of the W-band fundamental voltage-controlled oscillator in 0.13 μm SiGe BiCMOS technology for an automotive radar application. Oscillator provides fundamental oscillation range of 76.8 GHz to 81.2 GHz. According to simulation results phase noise is –89.3 dBc/Hz at 1 MHz offset, output power is –5.6 dBm and power consumption is 39 mW from 3.3 V source.

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