用于HD-DVD的PRML检测系统的设计与实现

Design and implementation of a PRML detectionsystem for HD-DVD

对用于高密度DVD(HD-DVD)光盘存储系统的部分响应最大似然(PRML)检测器的设计和实现进行了详细研究.通过比较光盘信道的线性模型与记忆长度为4—7的部分响应(PR)多项式的幅频特性,从提高PR均衡器和维特比检测器性能的角度,对目标PR的记忆长度及系数的选择进行了详细分析.仿真计算的信噪比-误码率曲线说明,当目标PR的记忆长度为7且与光盘信道模型的幅频特性接近时,PRML检测器的性能最优.还详细描述了PRML系统中维特比检测器的硬件结构,分析证明当目标PR的记忆长度增加时,维特比检测器的逻辑单元规模也会增加,但运算速度并不受影响.经实验验证,目标PR的记忆长度为7个的PRML系统比现有PRML系统的检测性能更好且处理速度也完全满足HD-DVD光盘存储系统的要求.

A PRML detector suitable for high-density DVD （HD-DVD） system is developed in this paper. After comparing the spectrum characteristics of the linear optical channel model with various PR polynomials （memory length from 4 to 7） ,the criteria of determining memory length and coefficients of target PR is given. The simulated SNR-BER curves show that the Viterbi detector＇ s performance is much better when the memory length of PR is seven. The architecture of a Viterbi detector in PRML system is also described. By computer simulation and experiments, it is proved that the performance and speed of the PRML system with memory length seven can completely satisfy the requirements of the HD-DVD system.