The signal is plotted by a fast Fourier transform “fft” to produce a frequency domain spectrum on in frequency range within DC to 50KHZ.
Each frequency-domain segment is then transformed from the frequency domain to the time domain to generate a corresponding time-domain segment.
The method also includes performing an operation on the data in the frequency domain to produce data in the frequency domain, where the data in the frequency domain is in the second order.
The light source needs to be modulated in the frequency domain or time domain.
The method involves composing a frame with a time domain and a frequency domain.
A filter unit (113) uses a number (N) of first coefficients, and equalizes the frequency domain signal in a frequency domain.
These time-domain samples are converted to K frequency-domain values representing the symbols Sp...Sp+K-1 by a time-domain to frequency-domain overlapped transform.
The FTN modulation scheme may be employed both temporally and in frequency (e.g., the frequency spacing of the channels may be tighter than the Nyquist frequency spacing condition.