A New Non-Coherent MIMO Scheme: Matrix Coded Modulation "MCM"

cet article a été publié dans la conférence IEEE ISCIT en Chine entre 10 et 12 octobre 2011This paper proposes a new space-time coding scheme for non-coherent MIMO systems. In this scheme, called Matrix Coded Modulation (MCM), a joint channel errorcorrecting code and space-time code is considered. Coherent systems are those for which Channel State Information (CSI) is available at the transmitters and/or at the receivers, and their performance strongly depend on the channel estimation. Generally, this CSI estimation requires the insertion of pilotsymbols in the transmitted frame which implies a spectral efficiency loss of the global system. The existing non-coherent MIMO systems like Differential Space Time Modulation (DSTM) suffer not only from the degradation of performance compared to coherent systems, but also from many constraints on the channel and the use of memory at reception. In the proposed MCM scheme, decoding can be achieved with or without CSI at the receiving antennas. Moreover, a low-complexity decoding algorithm is described and compared to the existing differential schemes

Spatial diversity in MIMO communication systems with distributed or co-located antennas

The use of multiple antennas in wireless communication systems has gained much attention during the last decade. It was shown that such multiple-input multiple-output (MIMO) systems offer huge advantages over single-antenna systems. Typically, quite restrictive assumptions are made concerning the spacing of the individual antenna elements. On the one hand, it is typically assumed that the antenna elements at transmitter and receiver are co-located, i.e., they belong to some sort of antenna array. On the other hand, it is often assumed that the antenna spacings are sufficiently large, so as to justify the assumption of independent fading. In this thesis, the above assumptions are relaxed. In the first part, it is shown that MIMO systems with distributed antennas and MIMO systems with co-located antennas can be treated in a single, unifying framework. In the second part this fact is utilized, in order to develop appropriate transmit power allocation strategies for co-located and distributed MIMO systems. Finally, the third part focuses on specific synchronization problems that are of interest for distributed MIMO systems