Flexible Hardware Emulator for Narrowband MIMO Channels with NLoS Non-Isotropic Scattering and Arbitrary Antenna Motion
Hardware channel emulators are essential for developing and testing transceiver prototypes in laboratory settings. They should be able to monitor the dynamic motion of the mobile terminal. This paper presents a narrowband Multiple-Input Multiple-Output (MIMO) channel emulator implemented on Field-Programmable Gate Array (FPGA). The proposed emulator is based on Non-Line-of-Sight (NLoS) non-isotropic scattering with arbitrary motion dynamics of the mobile terminal. Its standalone hardware architecture ensures the flexibility and scalability of further hardware realization. Our proposed emulator is validated by comparing the emulated statistics of the channel gain against simulated results under a circular antenna trajectory. The Probability Density Function (PDF) of the fading envelope is observed to perfectly match the theoretical Rayleigh distribution(stationary channel) and the auto-correlation function(non-isotropic scattering) also shows a close agreement. The successful alignment of the eigenvalue of the channel gain matrix indicates our proposed emulator can perform correct MIMO characteristics.