scholarly journals Diagnostic Analysis of Radio Propagation in UMTS Networks Using High-Resolution Angle-of-Arrival Measurements

2011 ◽  
Vol 53 (1) ◽  
pp. 66-75 ◽  
Author(s):  
Maurice R. J. A. E. Kwakkernaat ◽  
Matti H. A. J. Herben
1986 ◽  
Author(s):  
Vytas Kezys ◽  
Ed Vertatschitsch ◽  
Terry Greenlay ◽  
Simon Haykin

Technologies ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 9 ◽  
Author(s):  
Sardar Gulfam ◽  
Syed Nawaz ◽  
Konstantinos Baltzis ◽  
Abrar Ahmed ◽  
Noor Khan

Extension of usable frequency spectrum from microwave to millimeter-wave (mmWave) is one of the key research directions in addressing the capacity demands of emerging 5th-generation communication networks. This paper presents a thorough analysis on the azimuthal multipath shape factors and second-order fading statistics (SOFS) of outdoor and indoor mmWave radio propagation channels. The well-established analytical relationship of plain angular statistics of a radio propagation channel with the channel’s fading statistics is used to study the channel’s fading characteristics. The plain angle-of-arrival measurement results available in the open literature for four different outdoor radio propagation scenarios at 38 GHz, as well as nine different indoor radio propagation scenarios at 28 GHz and 38 GHz bands, are extracted by using different graphical data interpretation techniques. The considered quantifiers for energy dispersion in angular domain and SOFS are true standard-deviation, angular spread, angular constriction, and direction of maximum fading; and spatial coherence distance, spatial auto-covariance, average fade duration, and level-crossing-rate; respectively. This study focuses on the angular spread analysis only in the azimuth plane. The conducted analysis on angular spread and SOFS is of high significance in designing modulation schemes, equalization schemes, antenna-beams, channel estimation, error-correction techniques, and interleaving algorithms; for mmWave outdoor and indoor radio propagation environments.


2008 ◽  
Vol 56 (8) ◽  
pp. 2720-2729 ◽  
Author(s):  
Maurice R. J. A. E. Kwakkernaat ◽  
Yvo L. C. de Jong ◽  
Robert J. C. Bultitude ◽  
Matti H. A. J. Herben

2011 ◽  
Vol 11 (7) ◽  
pp. 2085-2105 ◽  
Author(s):  
J. C. Dunson ◽  
T. E. Bleier ◽  
S. Roth ◽  
J. Heraud ◽  
C. H. Alvarez ◽  
...  

Abstract. The QuakeFinder network of magnetometers has recorded geomagnetic field activity in California since 2000. Established as an effort to follow up observations of ULF activity reported from before and after the M = 7.1 Loma Prieta earthquake in 1989 by Stanford University, the QuakeFinder network has over 50 sites, fifteen of which are high-resolution QF1005 and QF1007 systems. Pairs of high-resolution sites have also been installed in Peru and Taiwan. Increases in pulse activity preceding nearby seismic events are followed by decreases in activity afterwards in the three cases that are discussed here. In addition, longer term data is shown, revealing a rich signal structure not previously known in QuakeFinder data, or by many other authors who have reported on pre-seismic ULF phenomena. These pulses occur as separate ensembles, with demonstrable repeatability and uniqueness across a number of properties such as waveform, angle of arrival, amplitude, and duration. Yet they appear to arrive with exponentially distributed inter-arrival times, which indicates a Poisson process rather than a periodic, i.e., stationary process. These pulses were observed using three-axis induction coil magnetometers that are buried 1–2 m under the surface of the Earth. Our sites use a Nyquist frequency of 16 Hertz (25 Hertz for the new QF1007 units), and they record these pulses at amplitudes from 0.1 to 20 nano-Tesla with durations of 0.1 to 12 s. They are predominantly unipolar pulses, which may imply charge migration, and they are stronger in the two horizontal (north-south and east-west) channels than they are in the vertical channels. Pulses have been seen to occur in bursts lasting many hours. The pulses have large amplitudes and study of the three-axis data shows that the amplitude ratios of the pulses taken from pairs of orthogonal coils is stable across the bursts, suggesting a similar source. This paper presents three instances of increases in pulse activity in the 30 days prior to an earthquake, which are each followed by steep declines after the event. The pulses are shown, methods of detecting the pulses and calculating their azimuths is developed and discussed, and then the paper is closed with a brief look at future work.


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