Digital signals are so much a part of everyone's day to day life and it makes processes like the quality of communication better over telephone lines. Although we still use analog signals today, they can be converted to digital signals through digital signal processing.
- Analog signal
Analog signals are electrical in nature and are continuous signals. Variations in the signal are created by having another signal affect the flow of the analog signal as in microphone devices wherein an analog signal passes through circuits and is disrupted by air pressure as it compresses the transducer when an actual sound is created such as speech. The sound is processed and amplified through the circuits and audio speakers. Processing analog signals are much simpler than processing digital signals and have higher density than its digital counterpart. A disadvantage though is that analog signals contain or pick up a lot of noise and distortion. Although it can be reduced by using shielding and grounding wires, there will still be some distortion left that could affect the quality of the signal.
- Digital signal
Digital signals are much cleaner than analog signals since it uses bits of information that can be read even when distorted. Essentially digital signals are sampled analog waveforms that are given mathematical values at certain points. The digital signals are then formed by binary numbers that are quantized or processed with precise values which is measured by bits. This is the sampling rate that is used in digital devices to present the digital signal output. An advantage of digital signals over analog signals is that it can correct itself when confronted with noise corruption. As in speech processing over a telephone line, the signal could suffer from distortions, but since digital signal is made up of bits it can correct errors and still deliver the signal correctly.
- Applications of digital signal processing
Signals should be filtered so its output is free from distortions or unwanted noise. The unwanted noise usually comes from electrical nuances such as dips in electrical voltage and affects the quality of the signal. Through digital signal processing the signal is filtered through digital circuits to omit the corrupted parts and improve the quality of the signal.
- Analog to digital converter
A device is used to convert analog signals to digital signals or a series of discrete levels. This device is commonly known as an analog to digital converter, which slices the analog signal into equal segments and measured for amplitude at the middle of each equal segment. A resistance ladder is used to find the right voltage to match the analog signal. When the resistance ladder lines up with the analog voltage it is matched further until there are very little or no differences between the analog and the digital signals, then you have the digital output.
Digital signal processing is found in almost all devices such as cell phones, audio and video recorders and players, modems and computers.