Macroscopic diversity in radiomobile systems is a technique in which the terminal is in parallel connection with two base stations. It is a fundamental element in the operation of third generation mobile networks using CDMA. (IS 95, UMTS, etc.). A representation of the propagation phenomena involved requires joint modeling of the two transmission channels. The article presents a very simple method for simultaneously measuring their impulse responses, developed for this purpose. This method was the subject of a patent. It can more generally be applied to any number of channels and should allow the reuse of already existing single-channel sounders.