Abstract
A new run-length-limited(RLL)code for optical disks is described. It is an asymmetrical(d_0, d_1)=(2, 1)code, i.e., its minimum mark length is three channel bits to maintain the read back signal power, and its minimum space length is two channel bits to maintain the partial-response maximum likelihood(PRML)performance. It encodes 8 user bits into 14 channel bits, i.e., it has a better window size. Compared with the EFMPlus code, the ARL code has a 0.7dB gain in the required SNR at a BER of 10^<-4>. The power spectal density in the servo frequency band is -23dB.
