SDR Implementation of a Real-Time Testbed for Future Multi-Antenna Smartphone Applications

With the equipment of mobile terminals with multiple antennas, a bandwidth-friendly approach for increasing data rate and reliability has become the main trend in the development of future fifth generation (5G). However, this scenario presents significant challenges in the antenna and hardware design. For further system development, building real-time testbeds is a desirable track given that this endeavor can demonstrate the possibilities and limitations of the technology. In this paper, we present the design, implementation, and evaluation of a multiple input, multiple output system with eight antennas at a mobile terminal on the basis a software-defined radio (SDR) platform. The system uses long-term evolution-like system parameters. We illustrate the hierarchical hardware architecture and the implementation features, including the timing and synchronization, the processing partitioning, and the performance indicators of a particular eight-antenna module, which could meet the demands of 5G smartphone applications. Link-level simulations corresponding to the designs are conducted to validate the feasibility of the system. Accordingly, the SDR-based testbed is implemented, and a series of experiments are carried out to test the performance of our design in realistic situations. The proposed system has experimentally demonstrated its capability to transmit four-independent high-definition video streams on the same time-frequency resource.