Unrolled Architectures for High-Throughput Encoding of Multi-Kernel Polar Codes

TL;DR

This paper introduces a flexible unrolled FPGA architecture for high-throughput encoding of multi-kernel polar codes, supporting various kernels and code lengths, with a Python tool for automatic HDL generation.

Contribution

It presents a novel unrolled encoding architecture for multi-kernel polar codes, enabling high-speed FPGA implementation with extensive code support and a Python-based HDL generator.

Findings

Achieved 1080 Gbps throughput at 270 MHz for N=4096 codes.

Supports 83 different polar code configurations with various kernel combinations.

Demonstrated flexible FPGA implementation with trade-offs between throughput and resource use.

Abstract

Over the past decade, polar codes have received significant traction and have been selected as the coding method for the control channel in fifth-generation (5G) wireless communication systems. However, conventional polar codes are reliant solely on binary (2x2) kernels, which restricts their block length to being only powers of 2. In response, multi-kernel (MK) polar codes have been proposed as a viable solution to attain greater code length flexibility. This paper proposes an unrolled architecture for encoding both systematic and non-systematic MK polar codes, capable of high-throughput encoding of codes constructed with binary, ternary (3x3), or binary-ternary mixed kernels. The proposed scheme exhibits an unprecedented level of flexibility by supporting 83 different codes and offering various architectures that provide trade-offs between throughput and resource consumption. The FPGA implementation results demonstrate that a partially-pipelined polar encoder of size N=4096 operating at a frequency of 270 MHz gives a throughput of 1080 Gbps. Additionally, a new compiler implemented in Python is given to automatically generate HDL modules for the desired encoders. By inserting the desired parameters, a designer can simply obtain all the necessary VHDL files for FPGA implementation.