# Experimental Evaluation of a MIMO Radar Performance for ADAS Application
## 5 Conclusions  
We have carried out several experiments with a MIMO radar AWR1863 from Texas Instrument in realistic scenarios with pedestrians and motorcycles in order to evaluate some critical points of its performance, such as the number of false targets, the accuracy in the localization of the targets, and the number of valid echoes received per second. These parameters are important for the usefulness of the radar itself and also for the use of the obtained data to make a fusion with the images captured by the cameras in a more complete ADAS system. We use a double CFAR filter, one for separating velocities and the other for separating targets by distance. We have used large values in the first of them, with \(\mathit{PFA}_{\mathit{velocity}}=0.2\)-0.3, and more restricted values for the second, with \(\mathit{PFA}_{\mathit{range}}\) between 0.1 and 0.001. The results show that there is a compromise in selecting the value for the two parameters because a too small number diminishes not only the false targets but also the good ones. The accuracy in range is generally good, although a small value for \(\mathit{PFA}_{\mathit{range}}\) helps to avoid disturbance in the measurements due to false or poorly estimated targets. The mean error in distance along the experiments is about 0.25 m for pedestrians and 0.5 m for the motorbike. We maintain some doubt about the usefulness of this radar model due to the fact that it is difficult to detect a pedestrian at a distance of more than 30 or 35 m. This maximum distance seems too short in a real traffic situation. The maximum error in the localization of targets cannot be estimated properly because it is not possible to discriminate between false targets and positions erroneously calculated due to the present noise. Moreover, assigning a singular echo to a particular target depends on some chosen criterion, probably at a further stage in the complete detection algorithm, but always with a certain degree of arbitrariness. We have noticed that the number of valid echoes per unit time falls significantly in more demanding measurements, i.e., with a lower PFA value chosen. In other measurements, however, it has been determined that this model can provide easily 50 frames per second and more. Finally, real-world statistics for the characterization of the mean error in distance and its variance could only be made in a more advanced state of development, when a camera was available that allowed grouping echoes in large targets, or, at least, in a later stage, using a neural network, performing the task of identifying targets, grouping echoes from them, and giving the position of these targets along their temporal trajectory. So, as a final conclusion, the performance of some neuronal network deducing consistently targets from the echoes or a fusion data algorithm using the images of a camera would be crucial to determining the validity of the system in a real ADAS system. This radar could be a candidate for such a device, with the only objection that it should be able to detect small targets (pedestrians or middle-size objects) at a greater range. Conceptualization, F.D., J.A.L. and A.L. ; methodology: F.D. and J.R.C. ; experimental work: S.T.-B., F.D. and J.A.L. ; software: F.D. and S.T.-B. ; validation: J.R.C., J.P. and A.L. ; writing--original draft preparation: F.D., S.T.-B. and J.A.L. ; funding acquisition, J.A.L. and A.L. All authors have read and agreed to the published version of the manuscript. This research was funded by Cappemini as part of the project \"Percepcion Inteligente para los Vehiculos Autonomos y Conectados\" (InPercept), financed by \"Centro para el Desarrollo Tecnologico Industrial\" (CDTI), Spanish \"Ministerio de Ciencia e Innovacion\", under grant number PTAS-20211011, co-founded by the European Union, NextGenerationEU, \"Plan de Recuperacion, Transformacion y Resilencia\". Raw data from the radar measurements are available on request from the corresponding author (FD).