Regular implementation algorithms of time domain aliasing cancellation

The authors propose two highly regular algorithms for realising the time domain aliasing cancellation (TDAC) technique. The first TDAC implementation, which is based on the fast discrete cosine transform, effectively adopts analysis and synthesis window functions in the transform structure. This implementation algorithm achieves the least computational complexity in TDAC processes. The second TDAC implementation, which extends Goertzel´s concept, uses a simple selectable-fixed-coefficient second-order infinite impulse response (IIR) filter to recursively achieve multichannel audio encoding and decoding processes. With a properly selected coefficient, this recursive implementation achieves a lower round-off-error than the current fast implementations and the direct implementation in finite wordlength. In recently developed high quality consumer products, the first algorithm is suitable to be realised in digital signal processing chips and the second one will be a better choice for VLSI implementation