  Over the past decade, audio coding technology has seen standardization and
the development of many frameworks incorporated with linear predictive coding
(LPC). As LPC reduces information in the frequency domain, LP-based
frequency-domain noise-shaping (FDNS) was previously proposed. To code
transient signals effectively, FDNS with temporal noise shaping (TNS) has
emerged. However, these mainly operated in the modified discrete cosine
transform domain, which essentially accompanies time domain aliasing. In this
paper, a unified noise-shaping (UNS) framework including FDNS and complex
LPC-based TNS (CTNS) in the DFT domain is proposed to overcome the aliasing
issues. Additionally, a modified polar quantizer with phase contrast control is
proposed, which saves phase bits depending on the frequency envelope
information. The core coding feasibility at low bit rates is verified through
various objective metrics and subjective listening evaluations.
