FFTlängden

FFTlängden, also known as FFT length, refers to the number of data points used in a Fast Fourier Transform (FFT) algorithm. The FFT is a computational algorithm that efficiently computes the Discrete Fourier Transform (DFT) of a sequence, or its inverse (IDFT). The length of the FFT, or FFTlängden, is crucial as it determines the resolution and accuracy of the frequency domain representation of the input signal.

The FFT length is typically a power of two, such as 256, 512, or 1024, due to the efficiency of the radix-2 algorithm. However, other lengths can be used with different algorithms, such as the Bluestein or mixed-radix algorithms. The choice of FFT length depends on the specific application and the characteristics of the input signal.

A longer FFT length provides higher frequency resolution, allowing for the detection of more closely spaced frequency components. However, it also requires more computational resources and may introduce longer processing delays. Conversely, a shorter FFT length offers lower frequency resolution but is computationally less intensive and faster.

In practical applications, the FFT length is often chosen based on a trade-off between frequency resolution, computational complexity, and processing time. For example, in audio signal processing, a common FFT length is 2048, which provides a good balance between resolution and computational efficiency. In radar signal processing, a shorter FFT length may be used to minimize processing delays.