Multirate Systems: Sub-band Coding

• A simple source coder is shown in Fig. 3.1. Here, the sampled speech is passed through a quantizer. The quantizer can be represented by a number of break points which partition the input signal amplitude into disjoint regions. The regions are specified by an index. The index representing a region can be mapped into a quantized value x̂[n] which is used for all input all signal values that fall into particular quantizer region. The quantizer index can be represented with a set of bits. For instance, if the number of regions is 256, the indices can be represented with 8 bits.