Sub-band coding of audio using recursively indexed quantization

A low-complexity audio data compression technique using sub-band coding (SBC) and a recursively indexed quantizer (RIQ) is proposed. The characteristics of the proposed system are investigated and several relevant implementation issues are described. The objective performance of the proposed system is compared to conventional coding techniques. A real time implementation of the proposed system running on a DSP microprocessor is also discussed. The results indicate that the RIQ-SBC system exhibits objective signal-to-quantization noise ratio 2 to 5 dB higher than other coders of similar computational complexity when processing a variety of wideband audio signals.