Packet loss concealment for mdct-based audio codec using correlation-based side information

In this paper, we investigate several methods for estimating the signal in lost packets of MPS audio using side information. First, we discuss packet loss concealment based on packet copy for an MDCT-based audio codec, and point out problems that deteriorate the quality of the restored signal. Then we propose a packet loss concealment 'method using sign correction. The proposed 'method uses signs of lower MDCT coefficients as redundant information, and the sign information is used when estimating the MDCT coefficients of the lost packets. Next, we propose a new method that uses the same side information as the sign correction method. Our method is a combination of one-bit quantization and sign correction, which has proved to be better than sign correction for improving the correlation between the original signal and the restored signal. The experimental results show that the proposed method outperforms the sign correction method. Next, we investigate several methods that use two bits for correcting one coefficient. The experimental results show that the combination of a two-bit correction and one-bit correction give the best result.