BER Minimization for AF Relay-Assisted OFDM Systems

We discuss bit error rate (BER) minimization problems in multiple amplify-and-forward (AF) relay-assisted orthogonal frequency-division multiplexing (OFDM) system over frequency-selective fading channels with total power and individual power constraints, respectively. A joint optimization method of power loading, relay selection and subcarrier pairing is solicited to solve the problems with respect to the above two power constraint conditions. Particularly, we transform subcarrier pairing into a linear assignment problem and apply Jonker-Volgenant (JV) algorithm to deal with it. A simulation result demonstrates superior performances of our algorithm to those of other schemes for different relay locations.