Characterization and simulation of mimo transport systems in tape

Abstract

The potential for significant capacity and performance improvements in tape storage systems appears to be substantial. Advances in several areas, however, are necessary to foster increases in linear and track densities and consequently achieve higher cartridge capacities and improved performance. Reliable and precise tape transport and track-following servomechanisms are of fundamental importance to guarantee best read-channel performance on all parallel data channels during tape operation. In particular, tight control of tension and potentially of tape-dimensional stability (TDS) variations will be necessary for moving to thinner tape material, which in turn will enable an increase in volumetric density. Figure 1 shows the block diagram of conventional tape transport and track-following servomechanisms in a tape drive. A digital dual servo channel provides estimates of the tape velocity, tape longitudinal position, and head lateral position, which are derived from signals read from dedicated servo bands [6]. Hall sensors provide tape velocity information from the individual reels, which typically is used in the absence of a valid velocity estimate from the servo channel. One of the main impairments affecting the performance of tape drives is the variation of tape tension, which may be induced by, e.g., reel eccentricities.