DVB-T ambiguity peaks reduction in passive radar applications based on signal reconstruction

This paper deals with the reduction of the ambiguity peaks that appear in the Cross Ambiguity Function used in a passive radar system, which uses DVB-T signals as Illuminator of Opportunity. Three methods are proposed, consisting in replacing the elements that are responsible of the ambiguity peaks, by other elements that do not give rise to periodic components. Ideal 64-QAM symbols, zero power components, and random segments with mean power equal to the acquired signal power, are used for this purpose. The obtained results show that a significant reduction of the ambiguity peaks is obtained, but with an undesired reduction in detection capabilities, due to the decrement in the main peak to pedestal level ratio.