Gradient descent based polarization channel estimation in extremely largescale MIMO systems
摘要
Accurate channel modeling and estimation are essential for enabling extremely large-scale multiple-input multiple-output (XL-MIMO) in 6G networks with ultra-high spectral efficiency. As the aperture of antenna arrays expands significantly in XL-MIMO systems, the electromagnetic propagation field transitions from the far-field to the near-field. To address this, we propose a Gradient Descent-based XL-MIMO channel estimation algorithm (GD-SOMP), which enhances estimation accuracy by transforming discrete sampling points into a continuous representation, aligning better with actual near-field XL-MIMO scenarios. Numerical simulation results demonstrate that the GD-SOMP algorithm achieves superior root mean square error (NMSE) performance compared to conventional near-field channel estimation methods.