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Radiated testing of massive multiple-input-multiple-output devices in fading radio-channel conditions is expected to be essential in the development of the fifth-generation (5G) base stations and user equipment (UE) operating at or close to the millimeter-wave (mm-wave) frequencies. In this paper, we present a setup upgrading the multiprobe anechoic chamber-based system designed originally for 4G UE. We describe methods for mapping radio-channel models onto the probe configuration and discuss the differences to the former 4G case. We also propose metrics to assess the accuracy of the test setup and find key design parameters by simulations. The results with the utilized channel models indicate that at 28 GHz, up to $16 \times 16$ planar arrays can be tested with a range length of 1 m and with at minimum eight active dual polarized probes. [ABSTRACT FROM AUTHOR]

Conducted cable setups have been dominantly utilized in the industry for performance testing of multiple-input-multiple-output (MIMO) terminals. The wireless cable method, which can achieve cable connection functionality without actual radio frequency cable connections, is a promising alternative. To date, the wireless method has been only discussed for $2\times 2$ MIMO terminals in the literature. However, the algorithm is not directly applicable for high-order MIMO terminals, due to the high computation complexity to determine the calibration matrix and high system cost to implement the calibration matrix. In this paper, an efficient particle swarm optimization (PSO) algorithm is proposed to determine the calibration matrix for high-order MIMO systems. Furthermore, a novel implementation of the calibration matrix in the radio channel emulator is proposed, which can significantly reduce the system cost. To validate the proposed algorithm, two MIMO mockups, each equipped with four antennas, were measured in an anechoic chamber. The measured results demonstrated the effectiveness of the PSO algorithm to establish wireless cable connections for $4\times 4$ MIMO terminals. [ABSTRACT FROM AUTHOR]

This correspondence discusses over-the-air (OTA) testing for multiple-input multiple-output (MIMO) capable terminals, with an emphasis on test zone size characterization for multi-probe anechoic chamber (MPAC) OTA configurations. For an MPAC setup, it is important to understand the test zone size that can be supported by its design. Further, it is desirable that the test zone size should be determined in terms of measured throughput deviation. However, such works have not been reported in the literature yet, due to challenges in practical MPAC setups. In this correspondence, we propose to simulate the MPAC OTA configuration and MS design in a channel emulator and perform MIMO throughput measurements in a conductive setup. With the proposed scheme, we can investigate how large a test zone can be supported for the synthetic MPAC configuration in terms of throughput deviation. This scheme is attractive, since various MS antenna designs and MPAC configurations can be flexibly selected and test zone size in terms of measured MIMO throughput deviation can be achieved. Measurement results show that with a high antenna correlation at the base station (BS) side, measured throughput results would be low, irrelevant to MPAC OTA designs and antenna designs at the MS side. Therefore, the antenna correlation at BS side should be set uncorrelated to ensure that true MS performance can be measured. Further, spatial correlation accuracy at the MS side becomes critical for throughput accuracy only when correlation values are in the high region (e.g., $\rho > 0.5$). [ABSTRACT FROM PUBLISHER]

Conventional conductive method, where antennas on the device under test (DUT) are disconnected from antenna ports and replaced with radio frequency (RF) coaxial cables, has been dominantly utilized in industry to evaluate multiple-input multiple-output capable terminals. However, direct RF cable connection introduces many practical problems and a radiated method to replace cable connection is highly desirable. Existing wireless cable method relies on the knowledge of a transfer matrix between the channel emulator (CE) output ports and DUT antenna ports, and also requires an anechoic chamber, which might be impractical and expensive. In this paper, a novel wireless cable method is proposed and experimentally validated. By recording the average power (i.e., reference signal received power in the long-term evolution) per DUT antenna port and selecting optimal complex weights at the CE output ports, a wireless cable connection can be achieved. The proposed method can be executed in a small RF shielded anechoic box and offers low system cost, high measurement reliability, and repeatability. [ABSTRACT FROM AUTHOR]

We derive a full measurement-based parametrization for a 3-D geometry-based stochastic channel model for an urban microcell type of environment at 10 GHz. The measurements were performed with a vector network analyzer and dual polarized virtual arrays at the bandwidth of 500 MHz. The proposed parametrization is validated by channel simulations. Multiple-input multiple-output channel is reconstructed from the measured data and compared with channel generated by the quasi deterministic radio channel generator using the proposed statistical parameters. The capacity and eigenvalue distribution are used as the validation metrics, showing almost perfect match between the reconstructed and simulated channels. [ABSTRACT FROM AUTHOR]

Massive multiple-input, multiple-output (MIMO) is seen as an enabling technology to fulfill dramatic improvements in spectral efficiency for fifth-generation (5G) deployment in 2020. For massive MIMO systems, the learning loop from early-stage prototype design to final-stage performance validation is expected to be slow and ineffective. There is a strong need to evaluate massive MIMO base station (BS) performance with over-the-air (OTA) methods. Until now, such OTA solutions have not been discussed for massive MIMO BS systems. [ABSTRACT FROM PUBLISHER]

This paper discusses over-the-air (OTA) testing for multiple-input–multiple-output (MIMO) capable terminals with emphasis on wideband MIMO channel capacity analysis in a multiprobe anechoic chamber setup. In the literature, the spatial correlation simulation accuracy at the receiver (Rx) side has been used to determine the test area size for a limited number of probes. However, it is desirable that the test area size is defined in terms of data rate deviation of the simulated channel in the laboratory from that of the target channel model. This paper reports MIMO capacity analysis results for wideband spatiotemporal channel models, with emphasis on the impact of the spatial correlation at the transmit (Tx) side, the channel model, and the spatial correlation at the Rx side on the capacity simulation accuracy. Simulation results show that the number of probes is irrelevant to capacity simulation accuracy when the spatial correlation at the Tx side is in the high region (e.g., \rho > \mbox0.7). Furthermore, when correlation at the Tx side is low, the spatial correlation accuracy is less critical with small correlation at the Rx side. The simulation results are further supported by measurements in a practical multiprobe anechoic chamber setup. The capacity simulation accuracy is shown to be a valid measure to determine the test area size. [ABSTRACT FROM AUTHOR]