Two New Algorithm for Millimeter-Wave Massive MIMO Channel Estimation Based on Lens Antenna Array

The use of multi-input multi-output (MIMO) systems in addition to increasing capacity, reducing the destructive effects of multi-path phenomena, reducing interference with other users, will lead to higher data rates. On the other hand, the use of millimeter-wave technology and work in high-frequency bands can prevent issues such as traffic and interference, and can significantly increase the data rates, spectral efficiency and the bandwidth. The millimeter-wave massive MIMO with the lens antenna array can significantly reduce the number of radio-frequency chains. In this paper, two novel algorithms are proposed for channel estimation in millimeter-wave massive MIMO. In this regard, a new algorithm using the compressive sensing based on the convex optimization is presented for channel estimation with high accuracy and low complexity. Then, the second new algorithm based on the greedy methods is provided. One of the benefits of this algorithm is its reduced computational complexity, and its high recovery speed. Finally, both proposed algorithms are compared with other existing algorithms. The simulation results confirm that the proposed algorithms outperform the existing algorithms.