Aliasing Issues in Sub Band Coding The general structure of Sub-Band Coding (SBC) is shown below:

The diagram shows that after each of the analysis filters, decimation is performed by a factor M which corresponds to the number of channels. Would this not result in aliasing when this decimation by N is performed for the higher frequency sub-bands and why is DDC not required in each path to translate each sub-band to baseband before performing the decimation and thus avoiding aliasing?
I think you're just misjudging what the [CHANNEL] block does: this is just saying &quot;all the bits that fall out of the different quantizers/encoders get transmitted&quot;.
It's especially not an adder! Most books actually show this just as a &quot;frame packer&quot; or &quot;interleaver&quot;.