用于高密度信息存储的RLL(4,11)编码设计

在分析现有光盘调制码的基础上，提出了一种3／8码率的游程长度受限码RLL(4，11)编码，比现有的EFM调制码的代码密度高出9．4％，并为这种编码设计了相应的编码器．在编码器设计中，提出了一种试探性的算法对状态图进行简化，将状态数降至14个，从而大大简化了编码和解码过程．还分析了这种编码的解码方法及其块解码器的窗口大小，估计了预期值的上限．由于这一编码在抑制直流成分上的不足，对应用此编码的系统进行了界定，最后给出了这个新编码的适用领域．

An RLL(4, 11) Coding Design for High Density Data Storage

Based on the analysis of modulation codes for optical disc, a 3/8 code rate RLL(4, 11) code is presented, whose density ratio is 9 4% higher than that of EFM The encoder of this code is designed A novel tentative algorithm is used in design of the encoder, which makes the number of encoder states reduce to 14, greatly simplifying the encoding and decoding process After that, the decoder of this code is discussed, and the window length of the sliding block decoder as well as the anticipation of FSTD(finite state transition diagram) are estimated Because this code is not a dc free modulation code, systems that use it must have some dc control measures Therefore, the situation that is more suitable to this code is characterized