Question

The average received power from a Mars spacecraft communications system by the Deep Space Network is 0.4 mW and the bit rate is 100 bits/second. If the average noise power spectral density is 10-6 joule, and optimum filtering is used, determine:

a. the bit error rate.

Answer 1

A precise calculation of the bit error rate (BER) for a Martian spacecraft's communications system requires additional information beyond the provided received power, bit rate, and noise power spectral density, such as the system's bandwidth and modulation technique.

Step-by-step explanation:

The student is asking about the bit error rate (BER) for a Martian spacecraft communications system given an average received power of 0.4 mW, a bit rate of 100 bits/second, and an average noise power spectral density of 10-6 joule, assuming optimum filtering. To find the BER, one would have to apply the Shannon-Hartley theorem, which relates the channel capacity (the maximum theoretically possible bitrate) to the bandwidth and the signal-to-noise ratio (SNR). However, additional information such as the bandwidth of the system or the required error-free threshold is needed to precisely calculate the BER. Without those specifications, an exact numerical answer for the BER cannot be provided. Generally, the BER might be determined from the SNR, which in turn can be derived from the received power and noise power spectral density, but these calculations often involve logarithmic expressions and are specific to the modulation technique used.

Answer 2

The bit error rate is approximately 0.

Step-by-step explanation:

To determine the bit error rate, we need to use the average received power and the average noise power spectral density. The formula for the bit error rate (BER) is:

BER = 0.5 * exp(-2 * SNR)

where SNR is the signal-to-noise ratio. In this case, the SNR is given by:

SNR = (received power) / (noise power)

Substituting the given values:

SNR = (0.4 mW) / (10^-6 J)

SNR = 4 x 10^5

Now we can calculate the BER:

BER = 0.5 * exp(-2 * (4 x 10^5))

BER ≈ 0

Therefore, the bit error rate is approximately 0.

The complete question is: The average received power from a Mars spacecraft communications system by the Deep Space Network is 0.4 mW and the bit rate is 100 bits/second. If the average noise power spectral density is 10-6 joule, and optimum filtering is used, determine:

a. the bit error rate. is: