  Multiple Input Multiple Output (MIMO) Orthogonal Frequency Division
Multiplexing (OFDM) is a promising transmission scheme for high performance
broadband wireless communications. However, this technique suffers from a major
drawback which is the high Peak to Average Power Ratio (PAPR) of the output
signals. In order to overcome this issue, several methods that require the
transmission of explicit Side Information (SI) bits have been proposed. In
fact, the transmitted bits must be channel-encoded as they are particularly
critical to the performance of the considered OFDM system. This
channel-encoding highly increases the system complexity and also decreases the
transmission data rate. For these reasons, we propose in this paper, two robust
blind techniques that embed the (SI) implicitly into the OFDM frame. First, we
investigate a new technique referred as Blind Space Time Bloc Codes (BSTBC)
that is inspired from the conventional Selected Mapping (SLM) approach. This
technique banks on an adequate embedded signaling that mainly consist on a
specific Space Time Bloc Codes (STBC) patterns and a precoding sequences
codebook. Second, in order to improve the signal detection process and the PAPR
gain, we propose a new efficient combined Blind SLM-STBC (BSLM-STBC) method.
Both methods have the benefit of resulting in an optimized scheme during the
signal estimation process that is based on the Max-Log-Maximum A Posteriori
(MAP) algorithm. Finally, the obtained performance evaluation results show that
our proposed methods result in a spectacular PAPR reduction and furthermore
lead to a perfect signal recovery at the receiver side.
