Approximately-Universal Space-Time Codes for the Parallel, Multi-Block and Cooperative-Dynamic-Decode-and-Forward Channels

Explicit codes are constructed that achieve the diversity-multiplexing gain tradeoff of the cooperative-relay channel under the dynamic decode-and-forward protocol for any network size and for all numbers of transmit and receive antennas at the relays. A particularly simple code construction that makes use of the Alamouti code as a basic building block is provided for the single relay case. Along the way, we prove that space-time codes previously constructed in the literature for the block-fading and parallel channels are approximately universal, i.e., they achieve the DMT for any fading distribution. It is shown how approximate universality of these codes leads to the first DMT-optimum code construction for the general, MIMO-OFDM channel.