engineering recuitment BEL Probationary Engineers Mock Test 2025 Communication Systems Random Processes Correlation and Power Spectral Density
If s(f) is the power spectral density of a real, wide sense stationary random process, then which of the following is always true?
1
s(0) ≥ s(f)
2
s(f) ≥ 0
3
s(-f) = -s(f)
4
\(\rm \int\limits_{ - \infty }^\infty {s\left( f \right)df = 0} \)