Quantization Adaptor for Bit-Level Deep Learning-Based Massive MIMO CSI Feedback
This work addresses the feedback overhead issue in massive MIMO systems for wireless communication, presenting an incremental improvement in quantization efficiency.
The paper tackles the problem of high feedback overhead in massive MIMO systems by proposing an adaptor-assisted quantization strategy for deep learning-based CSI feedback, achieving better quantization accuracy and reconstruction performance with less or no additional cost compared to state-of-the-art methods.
In massive multiple-input multiple-output (MIMO) systems, the user equipment (UE) needs to feed the channel state information (CSI) back to the base station (BS) for the following beamforming. But the large scale of antennas in massive MIMO systems causes huge feedback overhead. Deep learning (DL) based methods can compress the CSI at the UE and recover it at the BS, which reduces the feedback cost significantly. But the compressed CSI must be quantized into bit streams for transmission. In this paper, we propose an adaptor-assisted quantization strategy for bit-level DL-based CSI feedback. First, we design a network-aided adaptor and an advanced training scheme to adaptively improve the quantization and reconstruction accuracy. Moreover, for easy practical employment, we introduce the expert knowledge of data distribution and propose a pluggable and cost-free adaptor scheme. Experiments show that compared with the state-of-the-art feedback quantization method, this adaptor-aided quantization strategy can achieve better quantization accuracy and reconstruction performance with less or no additional cost. The open-source codes are available at https://github.com/zhang-xd18/QCRNet.