1 For an audio signal digitized at 44,000 samples per second with 16 bits per sample, (a) Evaluate the required raw bit rate.

 2.1 For an audio signal digitized at 44,000 samples per second with 16 bits per sample, (a) Evaluate the required raw bit rate. (b) If a vocoder reduces the rate to 10kb/s, what is the compression ratio, ratio of actual to raw rates?

2.2 Plot the received power of a line-of-sight link over distances from 100 m to 10 km, under the assumptions of 2 GHz carrier frequency, 3 dBi transmit antenna, 13 dBi receive antenna, and 5 mW transmit power.

2.3 The coldest recorder temperature on Earth in a natural environment is about -90 C. At what frequency, is the standard kB T for thermal noise power spectral density approximation wrong by 10 %?

2.4 By using the standard thermal-noise power-spectral-density approximation, plot the noise power in units of dBm for a temperature of 20 C for bandwidths from 1 kHz to 1 GHz.

2.5 For a system with 15 dBi antennas at both ends of the link, operating at a carrier frequency of 28 GHz, bandwidth of 100 MHz, temperature of 300 K, and transmit power of 1 mW, plot the SNR on a dB scale as a function of range for distances from 100 m to 100 km. 

3.1 For a system with 15 dBi antennas at both ends of the link, operating at a carrier frequency of 28 GHz, bandwidth of 100 MHz, temperature of 300 K, and transmit power of 1 mW, plot the capacity as a function of range for distances from 100 m to 100 km.

3.2 For a communications system operating at small SNR, what is the approximate achievable rate as a function of bandwidth B and SNR?