Channel probing in the uplink of OFDM-based wireless systems

In this paper, we consider a new channel probing scheme for opportunistic scheduling in the uplink of orthogonal frequency division multiplexing (OFDM)-based wireless systems. To reduce signaling overhead for the probing, we consider a two-step channel probing process; called pre-probing and mainprobing. Good subchannels are first estimated through the pre-probing process using a probing signal transmitted through subcarriers spread out the whole bandwidth. Then, by sending a main-probing signal over only good subchannels, the proposed scheme can significantly reduce the probing signaling overhead without noticeable performance degradation compared to the full probing scheme. Finally, the performance of the proposed scheme is verified by computer simulation.