Low-Complexity Hybrid Beam-Tracking Algorithms and Architectures for mmWave MIMO Systems

In the next-generation 5G system, millimeter wave (mmWave) multiple-input multiple-output (MIMO) system utilizes massive antennas at transmitter and receiver to increase the throughput and reliability. Due to the short wavelength of mmWave signals, more antennas can be adopted to alleviate severe channel path loss. However, the increase of RF chains raises the chip cost of the transceiver. Thus, hybrid RF beam-forming and baseband precoding scheme was proposed to reduce the RF chain number and complexity. This study presents a modified mmWave channel model by adding continuous drifting feature for mmWave system. This paper also proposes two pre-parallel index selection algorithms and architectures that can reduce the complexity by reusing previous precoder results and enables a parallel hardware architecture for the hybrid beam-tracking. The PPIS-MIB-SOMP and bit-stream-based PPIS-MIB-SOMP algorithms can reduce the complexity by 74% and 49%, respectively, in the 16x16 mmWave MIMO continuous tracking system.