Direct/Cooperative AF Relay Switching Using Spectrum Division/Adaptive Subcarrier Allocation for SC-FDMA Uplink
In this paper, the authors propose a Direct/cooperative Amplify-and-forward Relay (D/AR) switching using a Spectrum Division/Adaptive Subcarrier Allocation (SDASA) for increasing the uplink capacity of Single Carrier-Frequency Division Multiple Access (SC-FDMA). In the D/AR switching, switching between direct communication and cooperative AF relay is done so that the channel capacity is maximized. In the SDASA, the transmit SC signal spectrum is divided into sub-blocks, to each of which a different set of subcarriers (resource block) is adaptively allocated. They evaluate the achievable channel capacity by the Monte-Carlo numerical computation method. It is shown that the proposed D/AR switching can reduce the transmit power by about 4 (2) dB compared to the direct communication (the cooperative AF relay) for the 1% - outage capacity of 4.0bps/Hz.