MeerKAT correlator-beamformer: a real-time processing back-end for astronomical observations

The MeerKAT radio telescope consists of 64 Gregorian-offset antennas located in the Karoo in the Northern Cape in South Africa. The antenna system consists of multiple subsystems working collaboratively to form a cohesive instrument capable of operating in multiple modes for defined science cases. We focus on the channelizing subsystem (F-engine), the correlation subsystem (X-engine), and the beamforming subsystem (B-engine). In the wideband instrument mode, the channelizing can produce 1024, 4096, or 32,768 channels with correlation up to 64 antennas. Narrowband mode decomposes sampled bandwidth into 32,768 channels. The F-engine also performs delay compensation, equalization, quantization, and grouping and ordering. The X-engine provides both correlation and beamforming computations (independently). This document is intended to be a stand-alone entity covering the channelizing, correlation, and beamforming processes for the MeerKAT radio telescope. This includes data reception, pre- and post-processing, and data transmission.