FFT spectral leakage — causes, scalloping, and how windows help
Why FFT bins leak when tones miss bin centers, what scalloping loss is, and how windowing + ENBW trade leakage against noise bandwidth.
Signal Processing
Understand Moving Average Filter with Python & Matlab
This post contains interactive python code which you can execute in the browser itself. The moving average filter is a simple Low Pass FIR (Finite Impulse Response) filter commonly used for smoothing an array of sampled data/signal. It takes (L) samples of input at a time and takes the average of those (L)-samples and produces … Read more
BPSK modulation and demodulation — constellation, decision rule, and BER intuition
BPSK maps bits to opposite phases; coherent demodulation, decision rule, and links to the Q-function BER formula and interactive calculator.
Gibbs phenomenon — overshoot at Fourier discontinuities
Gibbs phenomenon: why partial Fourier sums overshoot near jumps, that the overshoot does not vanish with more terms, and a visual demonstration.