Separating returning radio signal sections from composite sum signal, for use in e.g. mobile radio network

摘要

A process for separating high-frequency radio signals from multi-layered composite signals operates on the principle of Fourier transformation. E.g. two signals (1,2) operating within the same predetermined frequency band and sent from two different transmitters (4,5), and are received as a composite signal (3) at a receiver (6). The received signal passes through an analogue/digital converter (7) and I-Q demodulator (8) to digital filters (9). The digital values are then converted with reference to their respective time zones, where the distance (T) between neighbouring time values is used in a Fourier transformation processor, where (T) is greater than the sampling interval. The DFT processor, preferably a special high-speed Fourier transformer based on the Cooley-Tukey-Radix or a Prime-Factor-FFT, changes the digital time zone reading into a spectrum, which is input direct into a data memory, before further processing. The signal sections are accumulated at difference frequency portions in the spectrum, enabling separation of the sections.