Quiz
Wireless Communications 2
Create a free account to finish this quiz
Save your progress and see your final score.
Already have an account? Sign in
Questions in this 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
Information
- Description
- HSR Vote Questions
- Author
- Jules Bärtschi
- Language
- English
- Views
- 109
- Tags
- Rating
- No ratings yet Rate this quiz