Annonce

Under this acronym, the MIMO concepts were first introduced in wireless communications field with two main goals:

• · To increase the data-rate throughput with same power / bandwidth;
• · Robustness to fading due to multiple paths, even take benefit of multiple paths.

At the beginning of the new millennium, the Radar community has elaborated on this concept in two variants, which may be combined together:

• · The “coherent MIMO” where the transmission and reception antennas are co-located. The word “coherent” means that the extent of the array is smaller than the diffraction lobe of the target, so that coherent spatial integration can be performed. The co-location of the transmission and reception antennas clusters is generally a sufficient condition to fulfill this.
• · The “statistical MIMO” were the antennas are spread over wider areas, and may operate on transmission, reception, or both. Unlike the previous case, this configuration allows spatial diversity.
• · For short range applications (eg imaging), use of sparse arrays, generally combined with Ultra-Wide Band signals optimisation of the point spread function of the sensor.