Polar-Coded Correlated MIMO System under Impulsive Noise Channels

In this paper, we present a performance analysis of polar-coded Multiple-Input Multiple-Output (MIMO) communication systems operating over spatially correlated Rayleigh fading channels in the presence of Symmetric Alpha-Stable (SαS) impulsive noise. The proposed configuration considers two antenna arrangements, namely 2×2 and 4×4, and compares the performance of three transmission schemes: uncoded MIMO with Minimum Mean Square Error (MMSE) detection, polar-coded MIMO employing Successive Cancellation (SC) decoding, and polar-coded MIMO employing Successive Cancellation List (SCL) decoding with a list size of 16. The SαS noise model is characterized by a characteristic exponent of α=1.5 and a reference dispersion parameter of γ=0.2, representing an impulsive non-Gaussian environment. The spatial correlation between antennas is modeled using an exponential correlation matrix at both the transmitter and receiver, enabling the investigation of propagation scenarios ranging from uncorrelated to highly correlated fading channels. The transmitted information is encoded using polar codes, modulated with Binary Phase Shift Keying (BPSK), and recovered through MMSE equalization followed by SC or SCL decoding. The system performance is evaluated in terms of Bit Error Rate (BER) as a function of the Signal-to-Noise Ratio (SNR) for different values of the spatial correlation coefficient, as well as BER versus the spatial correlation coefficient at a fixed SNR. The simulation results show that the incorporation of polar coding significantly improves transmission reliability compared to the uncoded MIMO system, with the SCL decoder consistently providing the best error-rate performance, particularly under severe impulsive noise and strong spatial correlation. Qualitatively, a lower characteristic exponent or a higher dispersion parameter corresponds to more severe impulsive noise and is therefore expected to increase the BER of all considered schemes, while the error-correction capability of polar coding, particularly with SCL decoding, provides increased robustness against such disturbances.