Large scale digital beamforming (LS-DBFs) are widely used in satellite com-munications for spectrum reuse and trans-mission enhancement. SRAM-FPGAs are a popular option for software defined satellite platforms due to their rich computation re-sources and high flexibility. However, they are sensitive to soft errors, which limit their appli-cation in space. This paper discusses the appli-cation of coding based fault tolerance schemes for the protection of LS-DBFs on software defined payloads. Since multiple FPGAs are usually needed to support the whole LS-DBFs system, different decomposition schemes are compared in terms of resource efficiency and reliability when the coding based scheme is applied to protect the DBFs on a FPGA. The-oretical analysis and hardware experiments shows that resource efficiency and reliability are a pair of contradictory requirements for decomposition schemes. The protection with vertical decomposition could improve the re-liability by 96％ with 1.5x redundancy. And the protection with horizontal decomposition could improve the reliability by 85％ with 1.2x redundancy.