| 231. | A digitized voice channel is made by digitizing a 4-kHz bandwidth analog voice signal. We need to sample the signal at twice the highest frequency (two samples per hertz). We assume that each sample requires 8 bits. What is the required bit rate? |
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Answer: (a).64 kbps
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| 232. | What is the bit rate for high-definition TV (HDTV)? |
| Discuss |
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Answer: (c).1.5 Gbps
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| 233. | A device is sending out data at the rate of 1000 bps. How long does it take to send a file of 100,000 characters? |
| Discuss |
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Answer: (d).800s
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| 234. | A file contains 2 million bytes. How long does it take to download this file using a 56-Kbps channel? |
| Discuss |
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Answer: (b).5-6 mins
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| 235. | We need to send 265 kbps over a noiseless channel with a bandwidth of 20 kHz. How many signal levels do we need? |
| Discuss |
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Answer: (d).128
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| 236. | Calculate the theoretical highest bit rate of a regular telephone line. The signal-to-noise ratio is usually 3162. |
| Discuss |
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Answer: (a).34.860 kbps
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| 237. | Calculate the theoretical channel capacity. If SNR(dB) = 36 and the channel bandwidth is 2 MHz. |
| Discuss |
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Answer: (b).24 Mbps
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| 238. | A channel has a 1-MHz bandwidth. The SNR for this channel is 63. What is the appropriate bit rate? |
| Discuss |
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Answer: (b).6 Mbps
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| 239. | A channel has a 1-MHz bandwidth. The SNR for this channel is 63. What is the appropriate signel level? |
| Discuss |
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Answer: (c).4
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