Pulse Code Modulation - Encoding, Quantization And Sampling
The importance of Encoding, Quantization, and Sampling in Pulse Code ModulationThere are mainly 3 basic operations that are carried out in pulse code modulation. They are encoding, sampling and quantization. Before knowing about the importance of encoding, quantization and sampling process in pulse code modulation, let us know a short description of pulse code modulation. It is a process in which a series of analog signals are converted into digital binary signals. This process is very useful in communication systems.
A whole pulse code modulation technique consists of encoding, quantization and sampling process. Therefore, these three operations (encoding, quantization, and sampling) play an important role in pulse code modulation.
3 Operations carried out in Pulse Code ModulationThe first step in pulse code modulation is sampling. It is very important in pulse code modulation as large varieties of analog signals are transmitted in a digital communication system in the form of block code words. Only the analog samples which are in the form of codewords are transmitted via a communication channel.
If the analog signals are not converted to block codes then it can't be transmitted in the channel. Sampling is essential for transmitting such analog signals.
The second main operation is termed as quantization process. Also, there are two important techniques in the quantization process. They are known as uniform quantization and non-uniform quantization. In the quantization process, the above discrete signals are denoted by a certain finite set of values. These set of values are also called finite amplitude levels. The uniform quantization and non-uniform quantization process are different.
In uniform quantization process, the series of sampled signals are quantized uniformly with equal intervals of time. Similarly, in the non-uniform quantization process, the series of sampled signals are not quantized uniformly with equal intervals.
There is an important role of Companding technique in the non-uniform quantization process.
Companding technique in Quantization process:
Companding is a special technique in non-uniform quantization process where compression of base-band signals and expansion of decoded message signals are carried out.
This companding technique is very useful in non-uniform quantization process for compressing purposes.
And, the last operation that is carried out in the pulse code modulation process is the encoding technique. There is an important role of encoding technique in pulse code modulation as it converts a sequence of input signals into the binary sequence so as to make easier to transmit in the digital communication channel.