Comparative Performance Analysis Of 2×2 And 4×4 QAM-Based MIMO-OFDM Systems For New Radio Indoor Signaling Over LTE Networks

Abstract

The increasing demand for high-throughput, low-latency, and reliable indoor wireless communication has accelerated the integration of New Radio (NR) waveform features within existing Long Term Evolution (LTE) network infrastructures. Indoor environments are particularly challenging due to severe multipath propagation, signal attenuation, and interference, which necessitate advanced transmission techniques to ensure precise and robust signal delivery. Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM), in conjunction with high-order Quadrature Amplitude Modulation (QAM), has emerged as a dominant physical-layer technology to address these challenges. This paper presents a comprehensive comparative performance analysis of 2×2 and 4×4 QAM-based MIMO-OFDM systems for New Radio indoor signaling over LTE networks. The performance evaluation is carried out under realistic indoor channel conditions, incorporating multipath fading and additive white Gaussian noise to emulate practical deployment scenarios. Key performance metrics, including bit error rate (BER), signal-to-noise ratio (SNR), achievable throughput, and spectral efficiency, are analyzed to assess the impact of antenna scaling and spatial diversity. The 2×2 MIMO-OFDM configuration is employed as a reference architecture, while the 4×4 MIMO-OFDM system is investigated to quantify the performance enhancements achieved through increased spatial multiplexing and diversity gain. Various QAM modulation schemes are considered to examine modulation robustness and error performance across different SNR regimes. Simulation results reveal that the 4×4 MIMO-OFDM system significantly outperforms the 2×2 configuration by achieving substantially lower BER and higher spectral efficiency, particularly in moderate to high SNR regions typical of indoor environments. The results also demonstrate improved link reliability and resilience against multipath fading when higher-order MIMO configurations are deployed. Although the 4×4 architecture introduces additional computational and hardware complexity, the observed performance gains justify its adoption for high-precision indoor NR communication within LTE-based networks. The findings of this study provide practical insights for the design and optimization of next-generation indoor wireless systems leveraging MIMO-OFDM and QAM modulation.