Generalized Weighted Sum Subtract Joint Detection for a Class of Multihead Multitrack Channels

Weighted sum subtract joint detector (WSSJD) was proposed by Fan et al. as an alternative way to implement maximum-likelihood (ML) detection for multihead multitrack (MHMT) systems. Different from the conventional ML detector, the trellis used in WSSJD is independent of the intertrack interference (ITI); therefore, WSSJD could efficiently adapt to the time-varying ITI environment. The channel transformation developed for WSSJD also naturally leads to a reduced-complexity implementation for the ML detector. In this paper, we generalize WSSJD to MHMT systems whose interference matrices satisfy the WSSJD property. The implementation details are given for a symmetric 3H2T system, as an example. Other interference matrices where WSSJD is applicable are also presented.