A New SAGE-Based Channel Estimation Scheme for Millimeter Wave MIMO-OFDM Systems with Hybrid Beamforming Techniques

A new two-stage channel estimation scheme based on the space-alternating generalized expectation-maximization (SAGE) algorithm is proposed for millimeter-wave (mmWave) massive multi-input multi-output (MIMO) channel sounding with hybrid beamforming (HBF) MIMO configuration. In the initialization stage, an iterative cancellation method is proposed to estimate the paths one by one, so it performs better than its counterparts on the channels with multiple paths. In the parameter iteration stage, the SAGE framework is used to refine the initial estimated results by iteratively updating the subsets of channel parameters. Simulation results demonstrate that the proposed algorithm achieves higher accuracy than the previously proposed channel estimation algorithm, especially in the low-SNR and the rich-scattering condition.