A method of orthogonal modulation of radar waves of a phase-modulated continuous wave radar system (10) by a sequence of numerical communication symbols. The method comprises steps of selecting (34) an equidistant bi-phased or multi-phased phase-modulation sequence, phase-modulating (46) the continuous radar wave of the radar system (10), and transmitting (48) the orthogonal phase-modulated continuous radar wave towards a scene. The method is characterized by the steps of generating (36) a detection sequence (s) by applying an outer coding (H) to the phase-modulation sequence, selecting(38) a communication range (C) in the complex number plane, based on the selected phase-modulation, generating (40) a communication sequence (c) comprising a plurality of sequence members, mapping (42) the communication sequence (c) into the communication range (C) by applying an injective mapping function (gamma) to the members of the communication sequence (c), and calculating (44) a numericalproduct of members of the detection sequence (s) with members of an image of the mapped communication sequence (c). The step of phase-modulating (46) the continuous wave of the radar system (10) is carried out according to the calculated numerical products.