Implementation of an SDR system using an MPI-based GPU cluster for WiMAX and LTE

This paper presents an implementation of a 2 x 2 Multi-Input Multi-Output Software Defined Radio (SDR) Base Station system using a Message Passing Interface (MPI)-based Graphic Processing Unit (GPU) cluster as its modem processor for a high-speed data processing. Recently, GPUs have been widely researched especially for SDR systems because of their capability for exploiting parallel processing using a large number of Arithmetic Logic Units. MPI-based GPU clusters have been adopted in order to further increase performance capability. From our experimental results, it has been found that the implemented system consisting of three GPU nodes can enhance the modem speed by more than 2.5 times compared to a single GPU system. A dual-mode Mobile Device (MD) prototype supporting Worldwide Interoperability for Microwave Access and Long Term Evolution communications systems is implemented. In our design, one of the two waveforms can automatically be selected by the MD itself using a dual-mode controller that determines the reconfiguration of the MD modem depending on the received signal quality.