Answer to Question #196179 in Electrical Engineering for Vijay

Question

Sketch the input-output characteristics of a compressor and expander

Answer 1

Companding is the act of compressing a signal at the transmitter and expanding it at the receiver (compression and expansion).

Companding compresses higher-amplitude analog signals until delivery and then expands them in the receiver.

Compression is accomplished with the aid of three functional blocks: Compressor, Uniform quantizer, and Expander, as seen in the diagram below in Fig1.

The compressor can compress the signal's dynamic range. High-dynamic-range signals will travel into components with low-dynamic-range capabilities. The uniform quantizer will quantize the compressed signal, and the expander can extend and invert the compression mechanism to recreate the original signal.

To replicate the signal at the receiver, the expander has complementary properties to the compressor so that the compressor input equals the expander output.

The input-output properties and curves of the companding mechanism are seen in Fig2 below, and it can be shown that companding is linear.

It aids in the removal of noise, distortion, and interference and the reduction of crosstalk speeds.

Companding aids in the enhancement of the dynamic spectrum of communication networks.

In telephony and other audio uses, companding is used.