Performance Analysis of Quantized MIMO in Correlated Hyper-Rayleigh Fading Environments

The presented research studies the impact of joint fading and correlation on the performance of a Multi-Input Multi-Output (MIMO) system utilizing linear precoding. The study addresses the challenges posed by low-resolution digital-to-analog converters (DACs) at the transmitter, which introduce significant signal distortion due to quantization effects. By incorporating a Lomax envelope fading model, which captures severe fading conditions often observed in hyper-Rayleigh regimes, the study provides a more realistic assessment of system performance. Various linear precoding schemes, including Zero-Forcing (ZF), Wiener Filtering (WF), and Maximum Ratio Transmission (MRT), are analyzed under different spatial correlation and quantization levels. The performance metric is evaluated in terms of average bit error rate (BER) using numerical simulations. Results indicate that Lomax fading significantly deteriorates system performance compared to Rayleigh fading, particularly in low-resolution DAC settings. Spatial correlation further degrades performance by reducing diversity gain, with MRT being the most affected due to its inability to mitigate interference. ZF and WF demonstrate superior error rate performance, with WF achieving the lowest BER at high signal-to-noise ratio (SNR) levels. Additionally, increasing the DAC resolution from 1-bit (L == 2) to higher levels (L == 32) substantially reduces quantization noise, enhancing overall system reliability. The conclusions drawn underscore the limitations of low-resolution DACs application in hyper-Rayleigh fading environments and the necessity of robust precoding strategies to mitigate performance degradation in practical MIMO implementations.