PRML Systems for Depth Multiplex Digital Magnetic Recording

对实现硬盘高记录密度的信号处理进行了研究，得到了以下结果。(1) R/W通道建模利用旋转台、任意波形发生器和数字存储示波器进行R/W实验，得到纵向和垂直记录通道的R/W模型。(2)采用双航迹记录的穿刺卷积编码PRML系统演示了采用半航迹宽度双航迹记录的穿刺卷积编码PRML系统。结果表明，该系统比单轨道的线性密度系统具有优势。(3)构建了高速率穿孔RSC码率8n/8n+1穿孔卷积编码器，并在turbo编码和迭代译码系统中进行了评估。结果表明，该系统具有瀑布式误码率特征。(4)开发了具有RLL约束的Turbo编码和迭代译码系统64/65(0,8)RLL码和保持RLL约束的Turbo编码系统。结果表明，采用64/65(0,8)RLL码和迭代译码系统的turbo编码比采用8/9（0,4/4）或16/17 (0,6/6)RLL码的turbo编码表现出更好的性能。

Studies of signal processing to achieve high recording density of hard disk drives were performedand following results were obtained.(1) Modeling of R/W channelModels of both longitudinal and perpendicualr recording channels were obtained by R/Wexperiments using a spinstand, an arbitrary waveform generator and a digital storage oscillo-scope.(2) Punctured convolutional coded PRML system using two track recordingPunctured convolutional coded PRML system using two tracks with a half track width was demonstrated. Results show the system has an advantage over the linear density of a system using one track.(3) High rate punctured RSC codeRate 8n/8n+1 punctured convolutional encoder for a serially concatenated turbo coding was constructed and evaluated in the turbo coding and iterative decoding system. The results show the system has a bit error rate characteristic such as a waterfall.(4) Turbo coding and iterative decoding system with RLL constraint64/65(0,8) RLL code and turbo coding system which keeps RLL constraint are developed. It is clarified that the turbo coding with 64/65(0,8) RLL code and iterative decoding system exhibits a good performance over that with 8/9 (0,4/4) or 16/17 (0,6/6) RLL code.