On MIDO Space-Time Block Codes

In this paper, the need for the construction of multiple input-double output (MIDO) space-time block codes (STBCs) is discussed, concentrating on the case of four transmitters for simplicity. Above the trivial method, i.e. switching off the extra layers in the usual multiple input-multiple output (MIMO) setting, two smarter yet simple MIDO construction methods are proposed. The use of these general methods is then demonstrated by building explicit, sphere decodable codes using two different cyclic division algebras (CDAs). We verify by computer simulations that the newly proposed methods perform extremely well as opposed to the trivial construction.