Çok Taşıyıcılı Çok Kullanıcılı MIMO Sistemlerin Kanal Kestirim Hatası ve Güç Yükselteci Etkisi Altındaki Performansı

Abstract

The multiple input multiple output (MIMO) architecture is crucial in improving the efficiency of wireless communication systems, making it a key element of various standards, including fifth-generation (5G) networks. Its importance is expected to grow in future-generation systems. Analyses of MIMO systems often rely on idealized assumptions, such as perfect channel estimation and the absence of hardware impairments. Yet, for realistic results, these factors must be accounted for. This thesis provides an in-depth analysis of the performance of multi-user MIMO (MU-MIMO) systems in wireless communications, with a focus on the effects of channel estimation errors and power amplifier nonlinearity.

The research starts with filter bank multi-carrier (FBMC) signaling, a potential alternative to OFDM and a candidate for non-cellular communication systems. It examines the influence of power amplifier nonlinearity on the downlink performance of MU-MIMO systems using FBMC. This part of the study derives the signal to distortion, interference, and noise Ratio (SDINR) and ergodic achievable rate for MU-MIMO-FBMC systems. Numerical results not only corroborate the analytical findings but also offer a comparative analysis of FBMC and traditional orthogonal frequency division multiplexing (OFDM) signaling in MU-MIMO systems with amplifier nonlinearity.

Furthermore, the thesis presents an analysis that evaluates the performance of MU-MIMO systems that use OFDM signaling, especially considering the combined impact of power amplifier nonlinearity and channel estimation errors. It includes a derivation of the closed-form SDINR and the ergodic achievable rate for maximum ratio transmission (MRT) and zero forcing (ZF) precoding schemes. Extensive numerical results support the analytical findings.