Implementation of a MIMO channel emulator for over-the-air LTE testing using software defined radio

Recent trends in road mobility (connected cars) indicate an increasing number of on-board radio communication systems like ITS-G5 or Long Term Evolution. Due to the relation between automobiles and mobile radio communication, these complex systems need to be tested repeatably and under realistic conditions. We pursue the approach of cluster-based channel emulation, implemented in a test setup employing a commercial software-defined radio module. This paper provides an overview of the internal structure and hardware architecture of the module Universal Software Radio Peripheral from National Instruments, describes the software implementation of the channel emulator in detail and verify results by over-the-air measurements in the virtual road simulation and test area of the Thuringian Center of Innovation in Mobility. One goal is to study the feasibility and applicability of the software-defined radio channel emulator implementation and to compare the performance with emulation by a commercial powerful communication testing device. The SDR implementation is based on a dedicated 3GPP standardized channel propagation profile. This paper augments the current research of realization of cluster-based channel emulation in anechoic chambers and their implementation on SDR modules.