Machine Learning for Model Order Selection in MIMO OFDM Systems
This work addresses a domain-specific problem for wireless communication systems, offering an incremental improvement in model order selection.
The paper tackles the problem of accurately estimating the number of multipath components in MIMO OFDM systems, which is crucial for channel estimation methods like MUSIC and ESPRIT, by proposing a machine learning method that achieves higher accuracy and enhanced reliability compared to state-of-the-art methods in almost coherent scenarios.
A variety of wireless channel estimation methods, e.g., MUSIC and ESPRIT, rely on prior knowledge of the model order. Therefore, it is important to correctly estimate the number of multipath components (MPCs) which compose such channels. However, environments with many scatterers may generate MPCs which are closely spaced. This clustering of MPCs in addition to noise makes the model order selection task difficult in practice to currently known algorithms. In this paper, we exploit the multidimensional characteristics of MIMO orthogonal frequency division multiplexing (OFDM) systems and propose a machine learning (ML) method capable of determining the number of MPCs with a higher accuracy than state of the art methods in almost coherent scenarios. Moreover, our results show that our proposed ML method has an enhanced reliability.