OGII: An Optimized Generalized Integrated Interleaved Decoder for Optical Disk Storage

Abstract

Optical disks are the ideal option for cold data storage because of their large capacity, extended lifespan, and low power consumption. To guarantee data dependability, strong error correction codes (ECCs) are needed since an increase in optical disk storage density raises the error rate. Generalized integrated interleaved (GII) codes based on Reed–Solomon (RS) codes can provide adequate data reliability at high code rates. However, the GII codes suffer from high decoding complexity due to nested decoding, which increases hardware resource consumption. Moreover, existing GII decoders are not optimized for the burst error characteristics in optical disk storage, limiting their error correction capability. In this paper, we propose an area-efficient OGII decoder architecture tailored for optical storage. The OGII decoder incorporates two key techniques: 1) a pipelining technique to reduce overall hardware resource consumption and 2) an error-erasure correction algorithm to enhance burst error correction capability. However, the key equation solver (KES) block remains the core component of the OGII decoder, and the introduction of the error-erasure correction algorithm increases complexity. Therefore, we propose a crisscross inverse-free Berlekamp–Massey architecture (CIBMA) to reduce hardware resource consumption and improve utilization efficiency in the core decoder module. Hardware implementation results demonstrate that under equivalent error correction capability, compared with traditional RS decoders in optical disk storage, the OGII achieves a 7.2% higher code rate and 15% lower power consumption with only $1.17\times $ hardware resource utilization. Simulation experiments under identical code rates show that with a raw symbol error rate of 0.02 and additional burst errors, the OGII decoder reduces block error rate by 4–5 orders of magnitude compared with conventional GII decoders, and 3–4 orders of magnitude compared with traditional RS decoders. For the core CIBMA module in OGII, it achieves at least 20% hardware resource reduction and 50% improvement in pipeline utilization efficiency compared with other architectures based on error-erasure correction algorithms.