AI 中文总结
研究游程长度受限码在BICM系统中的应用，聚焦低信噪比，推导优化问题得出最优分配方案，考虑渐近大的块长度推断实用策略，扩展到两状态RLL码并证明其性能显著提升。
AI 中文摘要
我们研究了游程长度受限（RLL）分组码在比特交织编码调制（BICM）系统中的应用。在此设置中，RLL码充当符号映射器，其输入比特与RLL符号之间的分配对性能至关重要。我们旨在优化RLL码的分配方案。RLL码的主要应用之一是减轻粗量化系统中的码间干扰（ISI）。然而，信道记忆和量化非线性使信息理论分析复杂化。为便于分析处理，我们考虑具有1位模数转换的分组信道，对单个RLL码块的传输进行建模。对于此信道，我们研究了BICM系统中可实现速率（即BICM容量）与RLL码分配方案之间的关系。聚焦于低信噪比（SNR）情况，我们推导了产生最优分配方案的优化问题。通过考虑渐近大的块长度，我们推断出针对具有有限块长度和块间干扰信道的RLL码的实用优化策略。此外，我们将此优化扩展到两状态RLL（TS - RLL）码，其提供比状态独立RLL码更高的码率。我们证明优化后的TS - RLL码相对于文献中的同类码表现出显著的性能提升。
英文摘要
We study the use of runlength-limited (RLL) block codes in bit-interleaved coded modulation (BICM) systems. In this setting, the RLL code acts as the symbol mapper, whose assignment between input bits and RLL symbols is critical for performance. In this work, we aim at optimizing the assignment scheme of RLL codes. One of the main applications of RLL codes is the mitigation of intersymbol interference (ISI) in systems with coarse quantization. However, channel memory and quantization nonlinearity complicate information theoretic analysis. To enable analytical treatment, we consider a block channel with 1-bit analog-to-digital conversion, modeling the transmission of a single RLL code block. For this channel, we investigate the relationship between the achievable rate in BICM systems-termed BICM capacity-and the RLL code's assignment scheme. Focusing on low signal-to-noise ratios (SNRs), we derive the optimization problem yielding the optimal assignment scheme. By looking at asymptotically large block-lengths, we infer a practical optimization strategy for RLL codes with finite block-length and channels with inter-block interference. Further, we extend this optimization to two-state RLL (TS-RLL) codes, which offer higher code rates than state independent RLL codes. We demonstrate that optimized TS-RLL codes exhibit significant performance improvements over literature counterparts.
Comments13 pages, 5 figures
