Error Rate Performance Analysis of the 5G NR Physical Uplink Shared Channels for Cell-Free Systems

This paper investigates the physical layer performance of 5G New Radio (NR) in a cell-free (CF) massive MIMO system, focusing on the transmission of the Physical Uplink Shared Channel (PUSCH) over frequency-selective Rayleigh fading channels. A comprehensive link-level simulator, compliant with 3GPP standards, is developed to evaluate the system’s performance across various scenarios. Key parameters such as subcarrier spacing (SCS), modulation and coding schemes (MCS) (QPSK, 16-QAM, 64-QAM, 256-QAM), and varying numbers of distributed radio units (RUs) are systematically analyzed. The results demonstrate the dual benefits of increasing the number of RUs: enhanced spatial diversity and improved proximity between user equipment (UE) and RUs, leading to significant improvements in reliability and error rate performance. The study also highlights the impact of higher SCS values in leveraging frequency diversity, particularly when signal bandwidth exceeds the channel’s coherence bandwidth. Practical channel estimation is incorporated to validate performance under realistic conditions. Block Error Ratio (BLER) is used as the primary performance metric, providing valuable insights into the interplay of spatial and frequency diversity in CF 5G NR systems, thereby confirming their potential to achieve robust and efficient communication in challenging wireless environments