High diversity with simple space time block-codes and linear receivers

Multiple-Input-Multiple-Output (MIMO) systems are under intense investigation for wireless transmission systems. Space-Time Coding is an efficient approach to exploit the huge diversity offered by the MIMO channel. One of the main problems of Space-Time Block Coding (STBC) is that the offered diversity can only be exploited by the optimal ML receiver which has exponential complexity. In contrast, linear receivers like the ZF-receiver are less complex, but achieve in general only a fraction of the offered diversity. In this paper, we show that it is also possible to achieve high diversity with linear receivers utilizing STBCs with a specific structure. We investigate the diversity properties of cyclic codes and extended Alamouti codes. It is shown, that the diversity order D increases asymptotically linear with the number of receive antennas (nR) and that the extended Alamouti code achieves already almost full diversity utilizing linear receivers and only small nR.