Hybrid Precoding with Data Stream Adaptation for High Throughput mmWave MIMO Systems

In this paper, we propose a practical hybrid precoding system to implement the MIMO transmission with data stream adaptation for high throughput millimeter-wave (mmWave) communications. Hybrid precoding by using both analog radio frequency (RF) precoding (beamforming) and digital baseband precoding is a practical way to achieve the required array gain and multiplexing gain, and to reduce system complexity of the mmWave systems. In the proposed hybrid precoding system, the number of data streams is adaptively adjusted based on the rank of the equivalent baseband MIMO channel matrix and the received signal-to-noise ratio (SNR) to guarantee a reliable communication with higher throughput. When the channel is not full rank due to geometrical change of transceiver, the proposed system can provide more data stream than rank at higher SNR by combining forward error correction (FEC) and spatial interleaver. Simulation results show that the proposed solution offers more throughput gain compared to the fixed data stream transmission and only rank-based adaptive method in mmWave hybrid precoding system.