Efficient Probe Weighting for MIMO OTA Testing Based on Douglas–Rachford Splitting Method

In over-the-air (OTA) performance testing, the multiprobe anechoic chamber setup is widely used to reconstruct the target channel by assigning appropriate weights to each probe. Most research relies on off-the-shelf solvers, such as CVX, to ensure accurate probe weighting. However, these solvers come with a substantial computational overhead due to their general-purpose nature. This letter presents the Karush–Kuhn–Tucker conditions for the probe weighting problem under the spatial correlation criterion. The conditions reveal the relationship between the closed-form solution and the optimal solution, thus casting insights into the solution structure. Subsequently, based on the aforementioned analysis and the Douglas–Rachford method, an efficient probe weighting algorithm is proposed. The simulation results demonstrate that the proposed algorithm achieves extremely high computational efficiency for probe weighting with the same level of accuracy as CVX while demonstrating strong scalability in practical applications.