Closed-form cramér-rao lower bounds of the Ricean K-factor estimates from I/Q data

Closed-form CRLBs are derived for estimates of the Ricean K-factor from I/Q data. Indeed, the CRLBs evaluate effectively the estimators and indicate the best approach to adopt. The CRLBs are derived in two cases. In the first case, only the Ricean K-factor is assumed unknown, while in the second case the Line-Of-Sight (LOS) phase, Angle of Arrival (AoA), Doppler shift and specular Doppler frequency shift are assumed unknown as well. We compare the obtained analytical expressions with numerical CRLBs. Simulation results show a perfect corroboration between analytical and numerical CRLBs.