Fast LDPC GPU Decoder for Cloud RAN

Abstract: The GPU as a digital signal processing accelerator for cloud RAN is investigated. A new design for a 5G NR low density parity check code decoder running on a GPU is presented. The algorithm is flexibly adaptable to GPU architecture to achieve high resource utilization as well as low latency. It improves over an existing layered design that processes additional codewords in parallel to increase utilization. In comparison to a decoder implemented on a FPGA (757K gate), the new GPU (24 core) decoder has 3X higher throughput. The GPU decoder exhibits 3 to 5X lower decoding power efficiency, as typical of a general-purpose processor. Thus, GPUs may find application as cloud accelerators where rapid deployment and flexibility are prioritized over decoding power efficiency.