Digital Signal Processing (DSP) is the use of digital processing to perform a wide variety of signal processing operations, most commonly audio signals. It manipulates analog information, such as audio or photographs that have been converted into digital form.
Digital signal processors, also referred to as DSP, are fundamental to digital technology and are found inside devices such as headphones, smartphones, smart speakers, and vehicle entertainment systems. DSP has many advantages over analog processing, such as error detection and correction in transmission and data compression.
How a DSP works
A signal requires processing so that the information it contains can be displayed, analyzed, or converted to another type of signal. A DSP takes real-world signals that have been digitized, such as voice, audio, and video, and then mathematically manipulates them into the digital format of 1’s and 0’s. The DSP processes this information and feeds it back for use in the real world. All of this occurs at high speed.
A DSP contains these primary components:
- Program memory: Stores the programs needed to process data
- Data memory: Stores the information to be processed
- Compute engine: Performs the mathematical processing, accesses the program from the program memory and data from the data memory
- Input/output: Serves a range of functions to connect to the outside world
A DSP can improve an audio signal in many ways:
- A/D, D/A (Analog to Digital, Digital to Analog) Conversion: A DSP can convert an analog signal to digital data, process the data, then convert it back to analog without affecting the audio quality. This allows a microphone to connect directly to a DSP without needing a separate device.
- Acoustic Echo Cancellation: A DSP can prevent unwanted echoes by subtracting the audio from the microphone’s signal before any echoes can occur.
- Automatic Gain Control: A DSP can automate and balance volume, so a signal never gets too loud or too quiet.
- Gating: A DSP can distinguish between necessary sound, such as voices, and unwanted noise, such as crinkling paper and footsteps. When noise is picked up by the microphone, the DSP algorithm will gate the microphone so that the unwanted noise does not interfere.