Quiz
Wireless Communications 2
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Fragen in diesem Quiz (73)
1How many known, classical methods for the generation of SSB signals are there?
- A1
- B2
- C3
- D4
2What is the key feature of a polar modulator?
- Aresistance to low temperature such as -50 degree Celsius
- Bseparate conditioning of amplitude and phase
- Cantenna signal is in polar coordinates
- Dis the same as a direct-conversion TX
3Which of the following statements is true?
- AThe diode detector is the most sensitive receiver.
- BThe diode detector is the most selective receiver.
- CThe diode detector is a non-coherent receiver.
- DThe diode detector is an FM receiver.
4Which of the following statements is true?
- AAn electrostatic field causes a magnetic field.
- BA magnetostatic field causes an electric field.
- CThere are no electric "charges".
- DThere are no magnetic "charges".
5Which of the following statements is true?
- AMagnetic field lines cannot be closed.
- BElectric field lines cannot be closed.
- CElectric field lines may end at charges.
- DMagnetic field lines may end at charges.
6In the far-field of an antenna the electric field strength decays as ...
- A1/r.
- B1/r^2.
- C1/r^3.
- DIt remains constant.
7The free-space impedance in vacuum is ...
- A0 Ohm
- B377 Ohm
- C500 Ohm
- DInfinite Ohm
8The polarization direction describes ...
- Athe direction of the E field.
- Bthe direction of the H field.
- Cthe direction of the Poyinting vector.
- Dthe propagation direction.
9For circular polarization the Poynting vector is ...
- Aradial to the circular plane.
- Baxial to the circular plane.
- Ctangential to the circular plane.
- Dthe same as the E-field vector.
10In the equivalent circuit of an antenna for max. efficiency we aim at making ...
- Athe radiation resistance smaller than the loss resistance.
- Bthe radiation resistance equal to the loss resistance.
- Cthe radiation resistance larger than the loss resistance.
- DDoes not matter.
11Which of the following statements is true?
- AYagi antennas are always horizontally polarized.
- BIsotropic radiators have the largest gain of all antennas.
- CA monopole is an isotropic radiator.
- DHelix antennas cause a rotating H field.
12The effective length of a Hertzian dipole is ...
- Asmaller than that of a halfwave dipole.
- Bequal to that of a halfwave dipole.
- Clarger than that of a halfwave dipole.
- Dtwice of that of a halfwave dipole.
13Which of the following statements is true?
- ARod antennas do not have an effective antenna area.
- BVertical rod antennas transmit towards the zenith.
- CSatellite dishes need to have a round shape.
- DA standard dipole is twice the length of a standard monopole.
14For free-space conditions the received power ...
- Ais reduced to 1/100 for every decade in frequency.
- Bis halved for every doubling of the distance.
- Cis multiplied by 4 for every doubling of the distance.
- Dis dependent on the received antenna only.
15The Taylor approximation of (1+x)^5 for small x is ...
- A1 + x +o(x^3).
- B1 + 5x +o(x^3).
- C1 + x^5 +o(x^10).
- D5 + x^5 +o(x^10).
16The path-loss exponent ...
- A... cannot be larger than 2.
- B... is normally a number larger than 1.
- C... is always zero.
- D... is in general a complex number.
17Thermal noise at room temperature is ...
- A-147.6 dBm/Hz.
- B-174 dBm/Hz.
- C-741 dBm/Hz.
- D-174 dBW/Hz.
18The principle of Huygens explains, why a wave ...
- Anever returns to its origin.
- Bcan penetrate a wall.
- Ccan reach locations without line-of-sight connection.
- Dflips the polarization sign in the case of reflexion.
19Which part of the first Fresnel zone shall be clear for unobstracted free-space conditions?
- A50 %
- B60 %
- C85 %
- D100 %
20For large distances the open-field loss becomes independent of ...
- Athe operation frequency.
- Bthe distance.
- Cthe BS antenna height.
- Dthe MS antenna height.
21How strong is thermal noise (room temp) in the whole FM braodcast radio band 88-108 MHz?
- A-99 dBm
- B-100 dBm
- C-101 dBm
- D-174 dBm
22What happens to reflexions at rough surfaces?
- AThey are enforced.
- BThey are scattered.
- CThey get absorbed.
- DThey remain unchanged.
23At what frequency will you find a water absorption peak?
- A2.4 GHz
- B22 GHz
- C60 GHz
- Ddoes not exist
24What is the distribution of path loss for shadowing?
- Auniform.
- Bnormal.
- Clog normal.
- DRayleigh.
25What is the power distribution for NLOS?
- ARayleigh
- BRice
- CChi-square
- Dnormal
26What is the amplitude distribution for LOS?
- ARayleigh
- BRice
- CChi-square
- Dnormal
27The BER for BPSK in a Rayleigh-fading channel is ...
- Ahigher than in an AWGN channel.
- Bequal to that of an AWGN channel.
- Clower than in an AWGN channel.
- Dno statement can be made.
28For RADAR, the reflected electric field strength propagates as ...
- A1/r .
- B1/r^2 .
- C1/r^4 .
- Dindependant of r.
29Christian Doppler (1803-1853) was a(n) ...
- AAustralian engineer.
- BDanish chemist.
- CGerman physician.
- DAustrian physicist.
30In order to detect 2 objects within a distance of 100m using pulse radar, the pulse length must be shorter than ...
- A3 us.
- B3 ns.
- C0.3 us.
- D0.03 us
31Which of the following measurement methods can be compared best with RADAR?
- ATime-domain reflectometry
- BNetwork analysis
- CSpectrum analysis
- DImpedance measurement
32What is the Doppler shift of a CW Radar at 3GHz for a speed of 20m/s?
- A200 Hz.
- B400 Hz.
- C200 kHz.
- D400 kHz.
33What method does an airplane altimeter use?
- APulse Radar.
- BCW Radar (unmodulated).
- CFMCW Radar.
- Dbarometric (air pressure).
34What kind of orbits are used for GPS?
- ALEO (low-earth orbit)
- BMEO (medium-earth orbit)
- CGEO (geostationary-earth orbit)
- DHEO (highly elliptical orbit)
35Which is NOT within the scope of GPS?
- Aremote localisation of war-relevant equipment
- Bown localisation of objects
- Cmeasuring of own speed
- Dtime synchronisation
36How long does the transmission of GPS ephemerides take?
- A20 ms
- B1 sec
- C30 sec
- D12.5 min
37What is the code length of a C/A signal?
- A10 chips
- B1000 chips
- C1023 chips
- D1024 chips
38The modulation of the GPS data is ...
- AFM
- BFSK
- CBPSK
- DQPSK
39What is the 0-to-0 bandwidth of a C/A signal?
- A920 kHz
- B1.023 MHz
- C2.046 MHz
- D10.23 MHz
40At what frequency does the Fourier transform of a sequence with a chip duration of 1ms have its first zero?
- A1 kHz
- B2 kHz
- C1 MHz
- D2 MHz
41What influence to the spectrum does an extension of the PRN sequence (same chip duration) have?
- Aincrease in the 0-0 bandwidth
- Bdecrease in the 0-0 bandwidth
- Cincrease of the spectral density
- Dno influence on the bandwidth
42How strong is the received GPS level under open sky?
- A-110 dBm
- B-130 dBm
- C-160 dBm
- D-200 dBm
43What is the SNR of a GPS signal at the receiver input in the best case?
- A43 dB
- B20 dB
- C-20 dB
- D-43 dB
44What does E-P-L mean in a GPS receiver?
- AExact-Proper-Loose
- BEnough-Poor-Little
- CEarly-Prompt-Late
- DEasy-Perfect-Loose
45What order of magnitude is the maximal Doppler shift in GPS?
- A100 Hz
- B5 kHz
- C35 kHz
- D1 MHz
46What is a reasonable choice for the frequency step size in a GPS receiver with an integration dwell time of 2ms?
- A1 Hz
- B10 Hz
- C100 Hz
- D1 kHz
47How does localization in the iPhone work?
- AGPS only
- BA-GPS and WLAN
- CGPS and Galileo
- Dnot at all
48In a cellphone, what kind of dynamics would you expect between the lowest indoor GPS signal and the highest GSM transmitted
signal?- Aless than 40 dB
- B90 dB
- C140 dB
- D190 dB and more
49How many satellites do you need at least to estimate your 3D position?
- A1
- B2
- C3
- D4
50What influence does the troposhere have on a GPS signal?
- Aadditional delay
- Bfrequency shift of the signal
- Ccancellation of the signal
- Ddirectional reversal of the propagation
51What influence does the motion of a SV have on the GPS signal?
- Anone
- Bfrequency shift of the signal
- Ccancellation of the signal
- Dadditional delay
52Which of the following error contributions is reduced using Differential GPS?
- ASatellite clock error
- BReceiver noise
- CImplementation loss
- DMultipath
53Which of the following Dilution Of Precision (DOP) values is the largest?
- AHDOP (horizontal DOP)
- BVDOP (vertical DOP)
- CPDOP (positional DOP)
- Dthey are all the same
54Which generation of mobile technology does GSM belong to?
- A1G
- B2G
- C3G
- D4G
55Which generation of mobile technology does LTE belong to?
- A1G
- B2G
- C3G
- D4G
56What does a shrinking of cell size lead to in a cellular system?
- Adecrease of co-channel interference
- Bco-channel interference remains the same
- Cincrease of co-channel interference
- Dnumber of basestations is reduced
57What advantage does the sectorization of cells in a cellular system have?
- Aless radiation
- Bmore handovers
- CC/I is improved
- DNone of the above answers is correct.
58Why does GSM not use soft handover?
- ADifferent cells use different frequencies.
- BThe mobile station uses more current.
- CThe mobile station radiates more.
- DNone of the above answers is correct.
59What is the peak power for the GSM-900 band (uplink)?
- A250mW
- B1W
- C2W
- D10W
60Which modulation scheme is used for GSM?
- A256-QAM
- B16-QAM
- CQPSK
- DG-MSK
61NATEL originally stood for ...
- ANachrichtentechnik/Elektrotechnik
- BNative Telephone System
- CNationales Autotelefonsystem
- DNorth American Telephony System
62EDGE is an improvement of ...
- AGSM
- BUMTS
- CLTE
- DWLAN
63HSDPA is an improvement of ...
- AGSM
- BUMTS
- CLTE
- DWLAN
64Who was Mr Erlang?
- AGerman physicist
- BDanish mathematician
- CAustrian engineer
- DAustrian comedian
65How much traffic in Erlang (E) does the average cellular customer generate?
- A2 mE
- B2 E
- C2 kE
- D2 TE
66For a traffic of 10 E and 10 channels, what is the blocking probability?
- A0
- B0.2
- C1
- D-1
67What component is the "filter" for stolen GSM handsets?
- AVisitor Location Register (VLR)
- BAuthentication Center (AUC)
- CEquipment Identity Register (EIR)
- DEidg. Justizdepartement
68LTE means ...
- ALong Time Evolution
- BLeast Time Evolution
- CLast- Transfer Evolution
- DLong Term Evolution
69With LTE Advanced 4G+ we can have downlink rates of up to ...
- A800 bps
- B800 kbps
- C800 Mbps
- D800 Gbps
70This is possible thanks to ...
- ACarrier Acceleration
- BCarrier Agriculture
- CCarrier Aggresiveness
- DCarrier Aggregation
71asut-Faktencheck 5G. What was their answer to the fake news: "5G erzeugt Krebs."?
- A5G ist gefährlicher als 4G.
- B5G ist weniger gefährlich als 4G.
- C5G ist weniger gefährlich als 3G
- D5G wird als möglicherweise krebserregend taxiert - genauso wie Kaffee.
72asut-Faktencheck 5G. What was their answer to the fake news: "In Den Haag starben Hunderte von Vögeln wegen 5GStrahlung."?
- ABeim entsprechenden Versuch war die Leistung zu stark eingestellt.
- BDie Vögel haben giftige Nadeln von Eibenbäumen gefressen.
- CDie Vögel haben giftige Beeren gefressen.
- DDie Vögel starben wegen der Varroamilbe.
73The uplink of LTE is operated using ...
- ASC-FDMA
- BCDMA
- COFDM
- Dnone of the above
Informationen
- Beschreibung
- HSR Vote Questions
- Autor
- Jules Bärtschi
- Sprache
- English
- Aufrufe
- 109
- Schlagwörter
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