Plane wave compensation technique for multiple‐input multiple‐output over‐the‐air testing in small multi‐probe anechoic chamber

Abstract

Multiple‐input multiple‐output (MIMO) over‐the‐air (OTA) testing is often executed in multi‐probe anechoic chamber (MPAC), the size of which is generally large enough so that the waves radiated from the probes can be considered plane waves in test area. The physical dimension of test setups is a key cost factor. In order to save laboratory space and reduce the cost, a compensation technique for spherical waves synthesising plane waves is proposed, which can be applied in small anechoic chamber. The object is to investigate the performances of the proposed plane wave compensation technique on MIMO terminal OTA testing in small MPAC. In the simulation, this technique presents good performances on various metrics, e.g. field distribution, spatial correlation, power angular spectrum estimation. As demonstrated in simulation, the ring radius of anechoic chamber can be reduced and the conventional far field criteria can be relieved.

On dynamic channel emulation in sector MPAC for over-the-air testing of beamformed massive MIMO devices

“…2) Probe Selection Method: Many probe selection algorithms have been proposed for the conventional twodimensional (2-D) MAPC setup and are mainly for stationary channel emulation [31] [32]. The common challenge of them lies in the computational complexity of emulating the dynamic propagations.…”

“…The common challenge of them lies in the computational complexity of emulating the dynamic propagations. For instance, the multi-shot algorithm [32] demands multiple high-dimensional convex optimizations due to a large number of available probes, and the PSO algorithm [31] requires even more computing time. [37] proposed a forward allocation (FA) algorithm based on the orthogonal matching pursuit (OMP) principle [38].…”

“…Compared to the stationary channel scenarios, the probe selection algorithm for the massive MIMO testing should not only be competent enough for the need for synthesizing accurate channels but also be computationally efficient to meet the need for dynamic emulation. However, the conventional high-performance probe selection algorithms are too time-consuming, such as the particle swarm optimization (PSO) method [31] and the brute force method [32].…”

On Efficient Non-Stationary Channel Emulation in Conductive Phase Matrix Setup for Massive MIMO Performance Testing

“…The algorithm combinations are shown in Table. I, where the particle swarm optimization (PSO) [33] is run several times to avoid local optima, and the probe location set, minimizing the weighted root mean square (RMS) spatial correlation error [11], is set to be the final location. The metric of PAS similarity is defined in [11].…”

Effective Sparse Recovery Framework for Ultrawideband Robust Plane Wave Generator

“…The basic principle of PWG is to coherently synthesize the plane wave field in the quiet zone (QZ) via properly allocating excitations for the contained antennas. Various methodologies, e.g., in [6][7][8][9][10][11][12], have been developed to determine the optimal locations and excitations of PWG antennas for a highquality and cost-effective plane wave synthesis. For example, a systematic guideline on the PWG geometrical design and the stability of the solution are studied in [9].…”