Patent ID: 8416730

Claim:
A method for relaying signals, comprising information coded as symbols, through a wireless network comprising a source node, a destination node and a series of relay nodes that extend between the source node and the destination node; the method comprising steps of: receiving a signal at a relay node and decoding the received signal; wherein, at the relay node, if the received signal is decoded incorrectly, employing an Amplify-And-Forward (AAF) relaying protocol comprising steps of amplifying the received signal and then transmitting the amplified signal to a next relay node, in which the relay node and the next relay node are designated as belonging to an AAF relay group; but otherwise, at the relay node employing a Decode-And-Forward (DAF) relaying protocol comprising steps of interleaving decoded symbols, re-encoding decoded symbols and then transmitting the coded signal to next relay node, in which the relay node and the next relay node are designated as belonging to a DAF relay group; wherein: all the relays in the AAF relay group amplify the received signals from the source node and forward them such that the received signals ultimately reach the destination, and all the relays in the DAF relay group decode the received signals, interleave the decoded symbols, re-encode and forward the received signals such that the received signals ultimately reach the destination; and, at the destination node: wherein all signals forwarded via the AAF relay group are combined together and with signals directly transmitted from the source and are sent to a first Maximum a Posteriori Probability (MAP) decoder; wherein all signals forwarded via the DAF relay group are combined together and sent to a second MAP decoder; wherein the first and second MAP decoders perform a turbo iterative decoding algorithm between the first and second MAP decoder to calculate an a posteriori probability of the information symbols representing the information symbols corresponding extrinsic information, whereby the extrinsic information of one decoder is used to update the a priori probability of the other decoder in the next iteration; and wherein, after a number of iterations, a decision is made regarding the information decoded from each symbol.