Interference-proof reception of radio signals using frequency hopping techniques

摘要

Two interference-proof techniques are shown for detecting binary radio sils transmitted by frequency hopping techniques. In the first, the decision as to which type of binary signal is being received is made by first comparing the energy on each mark and space channel with the energy contents of the same channels during a preceding baud which is blank except for jamming and interference, thus obtaining mark and space energy differences. The larger of these differences determines the type of signal received. In the other technique, the energy contents of both mark and space channels are compared with the energies received simultaneously on a nearby blank channel.