DPD and Compensation under RF Impairments in the Hardware by BiLSTM

In higher-order modulation and mmWave communications, radio frequency (RF) impairments, including amplifier nonlinearity, IQ imbalance, and phase noise are becoming serious problems in hardware devices. In this paper, we attempt to deal with RF impairments by Bi-directional Long Short-Term Memory (BiLSTM), including the improvements in digital pre-distortion (DPD) in the transmitter and compensation in the receiver. Characteristics of the RF device are considered to extract hidden laws and information in the fluctuation of RF devices, and the complexity is discussed. The simulation results show that the performance of the BiLSTM-based DPD and compensation for RF impairments are better than the traditional estimation. The data of DPD is collected from a universal software radio peripheral (USRP) with a 30 MHz bandwidth for authenticity.