Radio Astronomical Signal Preprocessing Technology in the Future

Radio astronomical signal preprocessing technology is a necessary operation before transmitting the digital signal to the recording system in astronomy. The intermediate frequency from the receiver contains several hundred megahertz to several gigahertz. If ADC is 8-bits quantization, the data rates from the ADC will be almost hundreds gigabit per second. The huge data can not be directly processed by a computer or a GPU. Radio astronomical signal preprocessing technology will make a solution. Nowadays, the radio astronomical signal preprocessing technology indicates polyphase filter bank implemented in FPGA, which channelizes the analog immediate frequency signal to several digital baseband. The digital baseband data can be make further preprocessed to simplify the valid data whose rate is less than the data directly from ADC, and then transmits the data to recording system. With the quickly development of computer technology, a single computer or a GPU server may process hundreds gigabit data directly from the ethernet per second in the future. It is begin to think about radio astronomical signal preprocessing executes in a computer or a GPU server in future. A simple astronomical radio signal preprocessing prototype is designed based on a GPU server in this paper. Polyphase filter bank module will make a move to GPU using float-point operation which is different from the fixed-point operation in FPGA. Float-point operation owns higher resolution than fixed-point operation, which is the key factor changing the polyphase filter bank module from FPGA to GPU. This research may act as a reference on the radio astronomical signal preprocessing in the future.