MCQOPTIONS
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MCQOPTIONS
This section includes 18 Mcqs, each offering curated multiple-choice questions to sharpen your Digital Communications knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Small scale fading occurs due to |
| A. | Doppler shift |
| B. | Time delay |
| C. | Doppler shift & Time delay |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 2. |
Channel noise is |
| A. | Additive |
| B. | White and stationary |
| C. | Has infinite bandwidth |
| D. | All of the mentioned |
| Answer» E. | |
| 3. |
Which needs more signal power? |
| A. | BPSK |
| B. | 16-QAM |
| C. | BPSK & 16-QAM |
| D. | None of the mentioned |
| Answer» C. BPSK & 16-QAM | |
| 4. |
Flat fading can be avoided or stopped by |
| A. | Error coding |
| B. | Equalization |
| C. | Adaptive bit loading |
| D. | All of the mentioned |
| Answer» E. | |
| 5. |
Channel's time spreading properties are |
| A. | Coherence bandwidth |
| B. | Signal dispersion |
| C. | Coherence bandwidth & Signal dispersion |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 6. |
Rake receiver does |
| A. | Counter effects multi-path fading |
| B. | Resembles equalizer |
| C. | Resembles equalizer & Counter effects multi-path fading |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 7. |
Uncorrelated fading occurs when |
| A. | Time span is small |
| B. | Time span is large |
| C. | Does not depend on time span |
| D. | None of the mentioned |
| Answer» C. Does not depend on time span | |
| 8. |
What are the types of small scale fading that occurs due to Doppler shift? |
| A. | Slow fading |
| B. | Fast fading |
| C. | Slow & Fast fading |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 9. |
In matched filter _______ is performed. |
| A. | Convolution |
| B. | Correlation |
| C. | Convolution & Correlation |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 10. |
Which noise component plays a role in decision making? |
| A. | Relevant noise |
| B. | Non relevant noise |
| C. | Relevant & Non relevant noise |
| D. | None of the mentioned |
| Answer» B. Non relevant noise | |
| 11. |
Decision making needs |
| A. | Priors |
| B. | Likelihoods |
| C. | Priors & Likelihoods |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 12. |
Block fading occurs in |
| A. | Frequency domain |
| B. | Time domain |
| C. | Frequency & Time domain |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 13. |
When a user's moving, the user's velocity causes shift in frequency. This is called as |
| A. | Doppler shift |
| B. | Frequency shift |
| C. | Velocity shift |
| D. | None of the mentioned |
| Answer» B. Frequency shift | |
| 14. |
A rake receiver uses multiple |
| A. | Delay circuits |
| B. | Correlators |
| C. | Detectors |
| D. | None of the mentioned |
| Answer» C. Detectors | |
| 15. |
Information reliability depends on |
| A. | Magnitude of each component |
| B. | Time of arrival of each component |
| C. | Magnitude & Time of arrival of each component |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 16. |
If coherence bandwidth is smaller than the bandwidth of the signal, _____ fading occurs. |
| A. | Flat |
| B. | Frequency selective |
| C. | Fast fading |
| D. | Time selective |
| Answer» C. Fast fading | |
| 17. |
Interleaving does |
| A. | Forward error correction |
| B. | Backward error correction |
| C. | Forward & Backward error correction |
| D. | None of the mentioned |
| Answer» B. Backward error correction | |
| 18. |
Coherence time is _______ to Doppler spread. |
| A. | Directly proportional |
| B. | Inversely proportional |
| C. | Not dependent |
| D. | None of the mentioned |
| Answer» C. Not dependent | |