Performance of Two-Hop Communication Links Employing Various Relay Processing Schemes

The error performance of a two-hop communication link (THCL) supported by a cluster of relay nodes (RNs) is investigated. The THCL includes one source node (SN) and one destination node (DN). The SN sends information to the DN via a cluster of RNs. At the RNs, signals received from the SN are processed based on one of the three relay processing schemes. The three relay processing schemes considered include the distributed relay processing, maximal-ratio combining (MRC)-assisted relay processing and the majority vote and equal-gain combining (MV-EGC) aided relay processing. For the MRC-assisted and MV-EGC aided relay processing schemes, information exchange among the RNs is supported by a local information exchange network, within which communicates are based on the principles of direct-sequence code-division multiple-access (DS-CDMA). In this contribution, the bit error rate (BER) performance of the THCLs is investigated and compared, when assuming that the first and second hops of the THCLs experience flat Rayleigh fading and that the communications within the local information exchange network conflict only Gaussian noise. We address the impact of the energy consumed for RNs´ cooperation on the achievable BER performance of the THCLs. Our studies demonstrate that, when the energy spent for cooperation is taken into account, cooperation among the RNs may impose a big trade-off on the achievable BER performance of the THCLs.