In this paper, we propose a novel subarray digital predistorter (DPD) with timely shared feedback for hybrid beamforming transmitters. This enables a set of power amplifiers (PAs) to be linearized with a single DPD. The output signal in the proposed DPD comprises the weighted combination of the inverse functions of the individual PAs from an array. Thus, the DPD output signal becomes simultaneously partially matched with all PAs. Computer simulation results demonstrate that better adjacent channel leakage ratio (ACLR) performances in the main beam direction can be achieved when all PAs have the same minimum ACLR level. In the proposed DPD, the ACLR level of an individual PA can be controlled by the weight selection in the DPD output signal. Thus, with the appropriate weight selection, all PAs in the array can have about the same minimum ACLR level. In contrast to current state-of-the-art solutions, the proposed DPD significantly reduces the complexity of hardware and power consumption, and can be easily extended for an arbitrary number of PAs in the subarray.
New Predistorter Architecture for Hybrid Beamforming Transmitter
2020-11-01
942562 byte
Aufsatz (Konferenz)
Elektronische Ressource
Englisch