An Efficient Receive-Diversity-Combining Technique for SC-FDMA-Based Cooperative Relays

In this correspondence, an efficient receive-diversity-combining technique is proposed for single-carrier frequency-division multiple access (SC-FDMA)-based cooperative relay systems when discrete Fourier transform (DFT) spreading sizes for mobile stations and relay stations are different. The proposed technique is composed of an adjustment block for the DFT spreading size, a phase rotation block, a resource reallocation block, a channel phase compensation block, a receive-diversity-combining block, a channel gain compensation block, and a resource de-allocation block. The proposed technique is shown to provide a high diversity gain in multipath channel environments with a relatively small computational complexity.