End-to-end antenna selection strategies for multi-hop relay channels

Multi-hop relay channels use multiple relay stages, each with multiple relay nodes, to facilitate communication between a source and destination. Assuming a low-rate feedback link from the destination to each relay stage and the source, this paper proposes end-to-end antenna selection strategies to achieve maximum diversity gain in a multi-hop relay channel. For the full-duplex case, end-to-end antenna selection strategies are designed and proven to achieve maximum diversity gain by using a single antenna path (using single antenna of the source, each relay stage and the destination) with the maximum signal-to-noise ratio at the destination. For the half-duplex case, two paths with the two best signal-to-noise ratios in alternate time slots are used to overcome the rate loss with half-duplex nodes, with a small diversity gain penalty. To increase the multiplexing gain, a multiple stream end-to-end antenna selection strategy for full-duplex multi-hop relay channel is also proposed, where multiple data streams are transmitted simultaneously using multiple paths from the source to the destination.