- scalar and vecor quantization
3.2 Scalar Quantization
Block diagram of PCM system:
Principle of PCM
3.3 Vector Quantization
When a set of discrete - time amplitude values are quantised jointly as a single vector, the process is known as a vector quantisation, also known as block quantisation or pattern matching quantisation.
Block diagram of a simple vector quantisation
- x =[ x1,x2,...xn] - N dimensional vector with real valued, continuous amplitude randomly varying components xk
- y - N dimensional vector chosen from finite set of values Y = yi (i< 1 < L)
- Y - codebook in reference tempalte
- L - size of the codebook
- yi - set of codebook vectors
- Ci - cells, and a vecor yi is associated with each cell Ci, and quantiser then assign the codebook vector yi if x is in Ci:
| q(x) = yi if x element of Ci |