Cooperative Transmission with a Slotted Incremental Decode-and-Forward Protocol

We investigate a slotted incremental decode-and-forward (SIDF) protocol for cooperative communication in wireless networks. In the proposed scheme, each user allocates only a portion of its time-resource to incrementally relay its partner´s information, thus to improve the bandwidth efficiency of the cooperative transmission. To analyze the performance, we derive the diversity-multiplexing tradeoff (DMT) of the SIDF protocol and show the optimal time-allocation. It is shown that the SIDF achieves the DMT upper bound for low and high multiplexing gain regions whereas it is slightly away from the upper bound at a medium multiplexing gain region. The superiority of the DMT of SIDF protocol is translated into significant improved outage probability, as compared with other well-known user-cooperation protocols.