Research on the ROACH2-GPU-Cluster-Based Correlator——Design and Implementation of an F-engine Model

Correlator plays an important role in radio interferometry astronomy. Traditional correlator is achieved with FPGA or ASIC. It calls for long development cycle and its flexibility is unsatisfactory. At present, more and more radio astronomy arrays adopt generic architecture correlator with FPGA system and GPU. In order to meet the demands of the ‘Tianlai’ project,we developed a new correlator based on ROACH2 and GPU cluster. We divided the workflow of the correlator into two parts:we let the high performance GPU undertake the CMAC (conjugate multiply and accumulate) and only left the ADC and FFT for the F-engine. This correlator has high flexibility and it is easy to control. It has been applied to the Tianlai project.