Source of this information:
In this design, in each RF-shielded rack is shared with 4 RF input signals, and then the 4 input signals are connected to the digital system. The connection between the analog and the digital is using a rj-45 connector, this is, the connection is done by a twin lead cable, each pair of twisted pair cables of the cat 7 cable has a RF signal. The RF signal goes to a ADC card, in the FPGA board. It uses x2 ROACH 2 FPGA to convert the analog signal into digital.