Performance of Symbol Combining with Constellation Change in Multihop Relay

This paper describes cooperative relay methods in multihop relay network. Relay symbol combination (RSC) is a method whereby a mobile station (MS) combines a direct signal from a base station (BS) with a signal received from a relay station (RS) under time diversity. Relay symbol combination with constellation change (RSCCC) is a method to improve performances of RSC with an additional procedure of constellation change in the relaying process. The simulation results show that these two techniques are effective in a relay system, but the performance gain largely depends on the positions of RS and MS relative to the BS.