Frekvensplass

Frekvensplass, or frequency space, is the coordinate system used to describe how a signal’s energy is distributed across frequencies. In the time domain, a signal x(t) can be analyzed in the frequency domain by its Fourier transform X(f), which shows how much of each frequency f is present and how its phase relates to the signal. The frekvensplass provides a compact view of the spectral content, with the magnitude spectrum |X(f)| indicating energy at each frequency and the phase information describing the alignment of frequency components.

The frekvensplass is typically obtained by transforming the signal from time to frequency domain. In digital signal processing, this is done with a discrete Fourier transform or fast Fourier transform, yielding a spectrum with discrete bins. Each bin k corresponds to a frequency f_k = k · Fs / N, where Fs is the sampling rate and N is the transform length. In two-dimensional signals such as images, the frekvensplass becomes a two-dimensional space with horizontal and vertical frequency axes.

Applications of frekvensplass include audio analysis, pitch detection, filtering, and modulation in communications, as well as spectral analysis in fields such as chemistry and physics. Identifying dominant tones or spectral features relies on locating peaks in the frekvensplass. Practical considerations include spectral resolution, leakage, and windowing, which affect how precisely frequencies can be resolved and how energy spreads between bins.

Frekvensplass is distinct from the time-domain representation, yet it is closely linked through the Fourier transform. It provides an essential framework for analyzing, interpreting, and manipulating the frequency content of signals.