Multipath Component Estimation with Hybrid Beamforming mmWave Architectures

The accurate estimation of multipath components in hybrid beamforming millimeter-wave systems is challenging due to limited spatial channel information and multiple beamforming sidelobes. High-resolution antenna array algorithms like SAGE and MUSIC, which typically rely on baseband signals from individual an-tennas, are impractical for architectures with fewer RF chains. This paper proposes a signal model that leverages baseband signals from multiple beam-steering directions to overcome hardware limitations. By adapting the SAGE and MUSIC algorithms to exploit joint transmitter (Tx) and receiver (Rx) beam-steering direction baseband sig-nals, we achieve effective multi path component parame-ter estimation. Monte Carlo simulations at 28 GHz show that both algorithms demonstrate strong performance, with the majority of absolute angular errors falling below 10 degrees. While MUSIC achieves higher pre-cision under certain conditions, its computational time increases with finer beamsteering resolution. In contrast, SAGE offers a more computationally efficient and robust solution, with a slight tradeoff in precision.