Improved power decoding of interleaved one-point Hermitian codes

An \(h\)-interleaved one-point Hermitian code is a direct sum of \(h\) many one-point Hermitian codes, where errors are assumed to occur at the same positions in the constituent codewords. We propose a new partial decoding algorithm for these codes that can decode—under certain assumptions—an error of relative weight up to \(1-\big (\tfrac{k+g}{n}\big )^{\frac{h}{h+1}}\), where k is the dimension, n the length, and g the genus of the code. Simulation results for various parameters indicate that the new decoder achieves this maximal decoding radius with high probability. The algorithm is based on a recent generalization of improved power decoding to interleaved Reed–Solomon codes, does not require an expensive root-finding step, and improves upon the previous best decoding radius at all rates. In the special case \(h=1\), we obtain an adaption of the improved power decoding algorithm to one-point Hermitian codes, which for all simulated parameters achieves a similar observed failure probability as the Guruswami–Sudan decoder above the latter’s guaranteed decoding radius.