A Scalable Correlator Architecture Based on Modular FPGA Hardware, Reuseable Gateware, and Data Packetization

TL;DR

This paper introduces a scalable, flexible FPGA-based correlator architecture utilizing modular hardware, open-source libraries, and Ethernet data packetization, enabling efficient processing for large radio telescope arrays.

Contribution

It presents a novel, scalable correlator design using standard Ethernet switches and open-source FPGA libraries, reducing implementation time and costs for large-scale radio astronomy signal processing.

Findings

Successfully deployed a 16-antenna correlator system

Achieved processing of 200-MHz bandwidth with 4-bit resolution

Demonstrated flexibility and scalability of the architecture

Abstract

A new generation of radio telescopes is achieving unprecedented levels of sensitivity and resolution, as well as increased agility and field-of-view, by employing high-performance digital signal processing hardware to phase and correlate large numbers of antennas. The computational demands of these imaging systems scale in proportion to BMN^2, where B is the signal bandwidth, M is the number of independent beams, and N is the number of antennas. The specifications of many new arrays lead to demands in excess of tens of PetaOps per second. To meet this challenge, we have developed a general purpose correlator architecture using standard 10-Gbit Ethernet switches to pass data between flexible hardware modules containing Field Programmable Gate Array (FPGA) chips. These chips are programmed using open-source signal processing libraries we have developed to be flexible, scalable, and chip-independent. This work reduces the time and cost of implementing a wide range of signal processing systems, with correlators foremost among them,and facilitates upgrading to new generations of processing technology. We present several correlator deployments, including a 16-antenna, 200-MHz bandwidth, 4-bit, full Stokes parameter application deployed on the Precision Array for Probing the Epoch of Reionization.