Layered Space- Time Index Coding

Multicasting K independent messages via multiple-input multiple-output (MIMO) channels to multiple users where each user already has a subset of messages as side information is studied. A general framework of constructing layered spacetime index coding (LSTIC) from a large class of space-time block codes (STBCs), including perfect STBCs, is proposed. We analyze the proposed LSTIC technique and show that it provides minimum determinant gains that are exponential in the amount of information contained in the side information for any possible side information at the receivers. When constructed over a perfect STBC, the proposed LSTIC is itself a perfect STBC and hence enjoys many desired properties.