DISTANCE ENHANCING CODES FOR E(2)PRML - PERFORMANCE COMPARISON USING SPINSTAND DATA

Two new RLL encoding schemes for the E(2)PR4 recording channel are ana lyzed experimentally. These codes, employing a d=0 run length constrai nt, simplify the detector complexity while achieving a higher code rat e than the traditional (1,7) recording code. They also maintain the sa me minimum squared distance, d(2) = 10, as the (1,7) code. Using spins tand data from an MR head, the new codes show an order of magnitude im provement in BER over (1,7) coded data in the range of UBD = 2.2 to 2. 6.