Design of SEU-Tolerant Turbo Decoders Implemented on SRAM-FPGAs

Turbo codes are widely used in satellite communications. When a turbo decoder is implemented on a field-programmable gate array (FPGA) in a space platform, it will suffer single-event upsets (SEUs) that can cause failures and disrupt communications. Therefore, the protection of turbo decoders implemented on FPGAs is important. In this article, first the reliability of an SRAM-FPGA-implemented turbo decoder to SEUs on user memory and configuration memory is evaluated based on fault injection experiments. Then, based on the features of the turbo decoder and the characteristics of the failures revealed by the reliability study, a duplication with comparison (DWC) scheme is proposed for the protection of the turbo decoder. Experimental results show that the reliability of the protected turbo decoder to SEUs on user memory and configuration memory is improved by 99.4% and 95.6%, respectively. The resource usage is about 2.2× that of an unprotected turbo decoder, which is significantly lower than the more than 3× required by the traditional triple modular redundancy (TMR) protection. Finally, the proposed scheme is compared with another two protection schemes.