Ricean K-factor estimation and investigation of urban wireless measurements

We consider the problem of estimating the K-factor of a Ricean fading wireless channel based on observations of the envelope only. An approximate Ricean power density function (pdf) is introduced to enable the derivation of a closed-form maximum-likelihood K-factor estimator. A further improved estimator is also proposed, featuring less bias and variance than the first one. The latter estimator outperforms closed form estimators found in the literature especially for low number of samples and/or large K-values. The estimator is applied to real wireless macro-cell urban-area measurements.