Hybrid Beam Combining for Massive MIMO Systems to Achieve Arbitrary-Shaped Beam Patterns

In this letter, a hybrid beam combining algorithm for arbitrary-shaped beam patterns in phase-only controllable massive MIMO is proposed. It enables precise control of beam combining gain in all directions based on the derived expression of non-stationary complex exponential signal, allowing for the generation of beam patterns with arbitrary geometric shapes. Both analytical and simulation results demonstrate the proposed algorithm can accurately approximate arbitrary-shaped beam patterns without compromising SNR performance compared with traditional methods. It becomes possible to achieve flexible beam training and sparse channel estimation algorithms for massive MIMO by these precise geometric shapes.