Partial DFT Codebook-Based Hybrid Precoding in Limited Feedback Millimeter Wave Massive MIMO Systems

Hybrid precoding techniques are a great way to reduce hardware costs for millimeter wave massive multiple-input-multiple-output (MIMO) systems. Limited feedback systems replace the transmission of many hybrid precoder parameters calculated at the receiver with a few codebook parameters, thereby saving information resource costs. In this letter, we explore how to improve hybrid precoder performance in limited feedback millimeter wave massive MIMO systems through codebook and algorithm design. We propose a partial DFT codebook and show that the approximation problem of hybrid precoders under partial codebook constraints can be transformed into an approximation problem under global DFT codebook constraints. We also propose an algorithm to solve the global approximation problem. Simulation results indicate that the proposed algorithm exhibits better spectral efficiency and lower computational complexity.