2604.01432 Fractional Fourier Transform Order Estimation from Chirp Signals Achieves Cramer-Rao Bound at SNR = -8 dB
Fractional Fourier transform (FrFT) order estimation from chirp signals achieves the Cram'er-Rao bound (CRB) at SNR = -8 dB using a maximum likelihood estimator with Newton refinement. Standard FrFT order search achieves CRB only at SNR $\geq$ 0 dB.