Techniques for supporting communication by a relay station are described. In an aspect, the relay station may support NACK Type 1 when operating in an amplify-and-forward (AF) mode. The relay station may receive a first transmission of a packet from an upstream station, determine PAPR of the first transmission, and send NACK Type 1 to the upstream station if high PAPR is detected. In another aspect, the relay station may support NACK Type 1 and NACK Type 2 when operating in a decode-and-forward (DF) mode. The relay station may perform PAPR decoding for the first transmission, send NACK Type 1 if PAPR decoding fails, perform channel decoding if PAPR decoding passes, and send NACK Type 2 to the upstream station if channel decoding fails. In yet another aspect, the relay station may operate in the AF mode or the DF mode.