The invention relates to a system and to the components thereof for carrying out signal processing operations including a synthetic aura which is suitable for presence detection and which the invention is to provide solutions enabling improvements in handling and user security to be obtained synergetically while producing comfort-increasing keyless access circuit systems. This aim is achieved, according to a first aspect of the invention, by means of a system for carrying out signal processing operations, taking into signals which are indicative of an area intrusion. Said system comprises means for generating the signals which are indicative of an area intrusion, based on electrical field interaction effects and circuit provisions, for automatic initiation of operations according to signals which are indicative of an area intrusion.