An adaptive distributed space-time coding (DSTC) scheme is proposed for two-hop cooperative MIMO networks in this project. Linear minimum mean square error (MMSE) receive filters and adjustable code matrices are considered subject to a power constraint with an amplify-and-forward (AF) cooperation strategy. In the proposed adaptive robust matrix optimization (ARMO) algorithm, an adjustable code matrix obtained by a feedback channel is employed to transform the space-time coded matrix at the relay node. The effects of the limited feedback and the feedback errors are assessed. Linear MMSE expressions are devised to compute the parameters of the adjustable code matrix and the linear receive filters. Stochastic gradient (SG) and least-squares (LS) algorithms are also developed with reduced computational complexity. An upper bound on the pairwise error probability analysis is derived and indicates the advantage of employing the adjustable code matrices at the relay nodes.
An alternative optimization algorithm for the adaptive DSTC scheme is also derived in order to eliminate the need for the feedback. Compared to the proposed centralized-ARMO (C-ARMO) algorithm, the novel algorithm provides a fully distributed scheme for the adaptive DSTC at the relay node based on the minimization of the error probability. The proposed fully-distributed ARMO (FD-ARMO) algorithm implements the optimization at the source node and can achieve a similar coding gain without the feedback as compared to the C-ARMO algorithms.
Members
- Tong Peng
- Rodrigo C. de Lamare
Dates
Start: October 2010
Research