ylinäytteistystä

Ylinäytteistystä, or oversampling, is a signal processing technique used to increase the sampling rate of a digital signal. This is achieved by inserting new samples between the existing ones. These new samples are typically derived from the original signal through interpolation. For example, a common method is to insert zeros between existing samples, a process known as zero-stuffing, and then apply a low-pass filter to smooth out the resulting sharp transitions.

The primary purpose of oversampling is to improve the signal-to-noise ratio (SNR) and to simplify the design of analog-to-digital converters (ADCs) and digital-to-analog converters (DACs). By oversampling, the quantization noise is spread over a wider frequency band, and a larger portion of this noise can be removed by filtering. This allows for the use of simpler, less steep analog filters, which are generally cheaper and easier to implement. In some applications, oversampling can also help to mitigate aliasing artifacts.

Oversampling is widely used in digital audio processing, telecommunications, and various measurement systems. In digital audio, it can lead to higher fidelity by reducing quantization errors and allowing for simpler anti-aliasing filters. In data converters, it enables the use of less precise analog components, reducing cost and complexity while maintaining or improving performance. The ratio of the new sampling rate to the original sampling rate is known as the oversampling ratio.