Distributed space-time coding strategies for wideband multihop networks: regenerative vs. non-regenerative relays

Distributed space-time coding (DSTC) is a rather novel paradigm that merges ideas from space-time coding (STC) and multihop networks (MHN) to design a wireless network capable of improving the performance considerably with respect to single hop networks (SHN). The basic advantage of DSTC comes from allowing multiple nodes to share their antennas to create a virtual transmit array and then implement a distributed space-time coding technique over the virtual array. The major differences between DSTC and conventional STC are: (i) detection errors at the relay nodes; and (ii) possible lack of synchronization between source and relay nodes. In this work, we study these problems and compare different DSTC techniques based on decode and forward and amplify and forward strategies. Finally, we show the trade-off curves between rate and diversity gain for DSTC systems.