What is the output of pulse code modulation?

What is the output of pulse code modulation?

The output of a PCM will resemble a binary sequence. The following figure shows an example of PCM output with respect to instantaneous values of a given sine wave. Instead of a pulse train, PCM produces a series of numbers or digits, and hence this process is called as digital.

What are the steps followed to achieve pulse code modulation?

The Pulse Code Modulation process is done in three steps Sampling, Quantization, and Coding. There are two specific types of pulse code modulations such as differential pulse code modulation(DPCM) and adaptive differential pulse code modulation(ADPCM).

Why companding is used in pulse code modulation?

For digital audio signals, companding is used in pulse code modulation (PCM). The process involves decreasing the number of bits used to record the strongest (loudest) signals. In the digital file format, companding improves the signal-to-noise ratio at reduced bit rates.

What is the quantization error in pulse code modulation PCM technique?

Pulse Code Modulation(PCM) • The error is called quantization error, thus the output of the quantizer is a digital level called q(nTs). • The quantized signal level q(nTs) is binary encode. The encoder converts the input signal to v digits binary word.

What is quantization in digital communication?

Quantization, in mathematics and digital signal processing, is the process of mapping input values from a large set (often a continuous set) to output values in a (countable) smaller set, often with a finite number of elements. A device or algorithmic function that performs quantization is called a quantizer.

What is quantization and quantization error?

Answer : Quantization error is the difference between the analog signal and the closest available digital value at each sampling instant from the A/D converter. Quantization error also introduces noise, called quantization noise, to the sample signal. S/N is the signal to noise and is expressed in dB.

What is companding and why it is used?

Companding is used in digital telephony systems, compressing before input to an analog-to-digital converter, and then expanding after a digital-to-analog converter. Companding also reduces the noise and crosstalk levels at the receiver. Companders are used in concert audio systems and in some noise reduction schemes.

Why is companding a necessary process in analog wireless systems?

In order to compensate for this, analog wireless systems employ a process known as “companding” to hide the dynamic range limitations of analog FM demodulation. Although companding improves the dynamic range, it also creates distortions (“artifacts”) that are often audible.

What is Pulse Code Modulation PCM explain how quantization levels are chosen in PCM?

In pulse code modulation, the analog message signal is first sampled, and then the amplitude of the sample is approximated to the nearest set of quantization level. This allows the representation of time and amplitude in a discrete manner. Thereby, generating a discrete signal.

Why quantization is important in digital communication?

This signal to get converted into digital, has to undergo sampling and quantizing. Quantization is representing the sampled values of the amplitude by a finite set of levels, which means converting a continuous-amplitude sample into a discrete-time signal.

What causes quantization error?

Error resulting from trying to represent a continuous analog signal with discrete, stepped digital data. The problem arises when the analog value being sampled falls between two digital “steps.” When this happens, the analog value must be represented by the nearest digital value, resulting in a very slight error.