A Method of Implementing a 4 × 4 Correlation Matrix for Evaluating the Uplink Channel Properties of MIMO Over-the-Air Apparatus

Abstract

This paper presents a method of implementing a 4 × 4 correlation matrix for evaluating the uplink channel properties of multiple-input multiple-output (MIMO) antennas using an over-the-air measurement system. First, the implementation model used to determine the correlation coefficients between the signals received at the base station (BS) antennas via the uplink channel is described. Then, a methodology is introduced to achieve a 4 × 4 correlation matrix for a BS MIMO antenna based on Jakes’ model by setting the initial phases of the secondary wave sources in the two-dimensional channel model. The performance of the uplink channel for a four-element MIMO terminal array antenna is evaluated using a two-dimensional bidirectional fading emulator. The results show that the measured correlation coefficients between the signals received via the uplink channel at the BS antennas using the proposed method are in good agreement with the BS correlation characteristics calculated using Monte Carlo simulation and the theoretical formula, thereby confirming the effectiveness of the proposed method.

Smart Gateway for Healthcare Networks Based on Beam Steering Technology

“…A spatial fading emulator is implemented using the Monte Carlo simulation [ 31 ]. In the fading emulator, the radio waves radiated from the scatterers, which are the controlled amplitude and phases of the signal used to emulate a Rayleigh fading channel, are summed around the evaluating antennas, and the desired radio environment is then generated [ 37 , 38 ]. Furthermore, when the signal radiated from the extra antenna is controlled according to the features of the direct wave, such as power and direction, a Rice propagation environment can be represented [ 39 ].…”

Over-the-Air Testing of a Massive MIMO Antenna with a Full-Rank Channel Matrix

“…On the other hand, an OTA testing method for massive MIMO MS antennas is not currently available. A fading emulator with a small number of scatterers placed on a circle has been adopted for proper OTA testing of a handset MS comprising a few MIMO antenna elements [ 15 , 16 ]. In the standard method utilizing a fading emulator, the arrangement of the scatterers depends on the number of subchannels, indicating that a large number of scatterers are necessary to assess the performance of a massive MIMO system with a full-rank channel matrix.…”