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Progressive channel estimation for ultra-low latency millimeter-wave communications

To leverage multiplexing gain, a hybrid beamforming architecture transmitting multiple data streams is widely adopted for Millimeter wave (mmWave) channel. However, for ultra-low latency mmWave communication, the hybrid design must require the development of instantaneous channel estimation. In this paper, we reveal a novel idea of progressive channel estimation through iteratively refining multiple training beams. By the proposed algorithm, the capacity gain can be strongly improved in short training time. Simulation shows that when reaching more than 80% capacity gain of exhaustive searching estimation, our work only spends 5% training time of exhaustive one. Aiming at ultra-low latency mmWave communications, the proposed algorithm is very suitable.