K-Factor Estimation for Wireless Communications Over Rician Frequency-Flat Fading Channels

Abstract

In this letter, a new method on the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${K}$ </tex-math></inline-formula> -factor estimation is proposed for wireless communications over Rician frequency-flat fading channels. Firstly, the mean and variance of the squared envelope of the received signal are respectively derived. Then, we employ them to further derive the closed-form expression for the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${K}$ </tex-math></inline-formula> -factor and finally present its estimation formula. Performance analyses, supported by Monte Carlo simulation results for a range of channel conditions, reveal that our proposed estimator outperforms prior techniques, and illustrate the approximate robustness of our suggested work to the signal-to-noise ratio, maximum Doppler shift, and angle of arrival without considering <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">a priori</i> knowledge.