  This paper presents the speech restoration and enhancement system created by
the 1024K team for the ICASSP 2024 Speech Signal Improvement (SSI) Challenge.
Our system consists of a generative adversarial network (GAN) in complex-domain
for speech restoration and a fine-grained multi-band fusion module for speech
enhancement. In the blind test set of SSI, the proposed system achieves an
overall mean opinion score (MOS) of 3.49 based on ITU-T P.804 and a Word
Accuracy Rate (WAcc) of 0.78 for the real-time track, as well as an overall
P.804 MOS of 3.43 and a WAcc of 0.78 for the non-real-time track, ranking 1st
in both tracks.
