A robust noise power and SNR estimator for MCIK OFDM systems over-generalised α-μfading channel with imperfect CSI

Abstract

Estimating the noise power and signal-to-noise ratio (SNR) are the core issues in any communication system. This paper introduces a novel algorithm to calculate the noise power and SNR for multi-carrier index keying (MCIK)-based orthogonal frequency division multiplexing (OFDM) systems operating over a generalised $\alpha$-$\mu$ fading channel. The impact of imperfect channel state information (CSI) uncertainty on the performance of the proposed estimator is investigated. An efficient algorithm is introduced on the transmitter side to transmit the nulled subcarriers effectively. Similarly, another effective algorithm is developed at the receiver side to identify the position of transmitted nulled subcarriers, as these positions are not fixed in the MCIK OFDM system. The average SNR, along with the average noise power is determined. The proposed estimator’s performance is compared with the Preamble, Boumard, Ren’s, Pilot, MMSE, CAZAC, and correlation-based CP-less estimators of OFDM systems. Additionally, the performance is also analysed using mean square error (MSE). The proposed estimator significantly improves spectral efficiency (SE) and energy efficiency (EE). It also achieves lower MSE over the existing estimators.