Question

The NPR for an SDR can be determined by matching the radio noise floor to the ADC input noise level.

(a) True

(b) False

The question was posed to me in an internship interview.

This intriguing question comes from ADC Tradeoffs topic in division Technology Tradeoffs in Software Defined Radio of Cognitive Radio

Answer 1

Correct answer is (b) False

Explanation: The SNR and DNR can be determined by matching the radio noise floor to the ADC input noise level. This imposes the design rule that the total noise power should be less than half of the least significant bit of ADC. The ratio of spectral density outside the notch filter to the maximum spectral density inside the notch filter gives the Noise Power Ratio.