Multi-variate block polar quantization and an application to audio

Abstract

We introduce multi-variate block polar quantization (MBPQ). MBPQ minimizes a weighted distortion for a set of complex variables representing one block of a signal under a resolution constraint for the entire block. MBPQ allows for different probability distributions in different dimensions of the set of complex variables. It outperforms a block polar quantizer introduced earlier (Pobloth, H. et al., Proc. Eurospeech, p.1097-100, 2003), and unrestricted polar quantization (UPQ), for both Gaussian complex variables and sinusoids found from audio data. In the case of audio data, we found a performance gain of about 2.5 dB over the best performing conventional resolution-constrained polar quantization, UPQ.