Cooperative relay systems have drawn much attention in recent years because they can use an appropriate number of relays to form a virtual multiple-input multiple-output (MIMO) scenario to improve communication links. Also, space frequency block coding (SFBC) is a prominent strategy for MIMO systems, and it has been widely adopted with orthogonal frequency division multiplexing (OFDM) to achieve both spatial and frequency diversity. One major problem associated with an SFBC-OFDM cooperative relay system is the existence of multiple carrier frequency offsets (CFOs), and this would cause serious intercarrier interference (ICI) and degrade the system performance greatly. In this paper, an improved transceiver design is proposed for two-relay SFBC-OFDM cooperative relay systems, where a modified SFBC encoder is adopted at the transmitter and a common CFO compensation unit, a modified SFBC decoder, and an iterative partial parallel interference cancellation (PIC) module are used at the receiver. The proposed design is computationally efficient and has a superior tolerance range of multiple CFOs. Simulation results demonstrate that it achieves better performance than previous related works.
['Chin-Liang Wang', 'Kuan-Yu Chu']
An Improved Transceiver Design for Two-Relay SFBC-OFDM Cooperative Relay Systems