In recent years, relaying networks are promising for future wireless communication systems, which profoundly enhance link capacity and exploiting cooperative diversity. In this paper, we propose a prototype of a Decode-&-Forward (D&F) Relay Node system based on Software Defined Radio (SDR) using Universal Software Radio Peripheral (USRP) and Matlab software. The developed testbed platform allows implementing and test new algorithms and specifications for LTE/LTE-A and 5G. Both Single-Input Single-Output (SISO) and Multi-Input Multi- Output (MIMO) are supported in our testbed. The considered D&F MIMO cooperative system in this paper utilizes Orthogonal Space-Frequency Block Codes (OSFBCs) for the transmission of the data symbols of the source to the destination. The transmission data from eNB has been measured using commercial 4G/5G measurement equipment. It has been demonstrated that D&F cooperative system substantially improves the Bit Error Rate (BER) and throughput of the user, taking higher performance with the 2×2 MIMO technique.