Helical scan tape recording with MLSE at 3600 bit/mm

A modified helical scan tape recorder was used for experimental digital recording. Demodulation was carried out using MLSE (maximum-likelihood sequence-estimation) with the Viterbi algorithm. Clock recovery is included in the estimation algorithm. A recording density of 3600 bit/mm was reached with low error frequency. The most important parameters were sampling frequency for the clock recovery and quantizing resolution for the decision process. Pulse interference width and path memory depth were investigated.<>