NDA moment-based SNR estimation for envelope-based QAM

This paper investigates non-data-aided (NDA) SNR estimation for envelope-based QAM transmission. It proposes a new technique to estimate the signal-to-noise ratio (SNR) using the well-known moment-based M₂ M₄ M₆ method over the flat-fading channel. This is a non-data-aided, envelope-based estimator that can be applied to non-constant modulus constellations. The performance of the proposed estimators is evaluated for rectangular 16-QAM modulation, the simulated performances are analyzed and compared for complex AWGN that is derived here.