Distributed IDM-STC versus Cooperative OFDM for the Two-Hop Decode-and-Forward Multiple-Access Relay Channel

This paper deals with the performance of two different access techniques for the Two-Hop Decode-and-Forward (DF) Multiple-Access Relay Channel (MARC) which includes multiple source and relay nodes. In particular, cooperative Orthogonal Frequency Division Multiplexing (cOFDM) is compared with distributed Interleave Division Multiplexing Space-Time Codes (dIDM-STC). While cOFDM requires strict synchronization in time and frequency among all communicating nodes, it allows for a rather simple detection structure. dIDM-STC, on the other hand, is very robust against timing and frequency offsets among the communicating nodes, however, requiring a more complex iterative detection. Both techniques are discussed in detail and are compared in terms of frame-error-rates (FER) and end-toend throughput by numerical evaluations.