Channel sounding for multi-sector cooperation in OFDM-based wireless cellular systems

In this paper, we consider channel sounding for multi-sector cooperative beamforming in orthogonal frequency division multiplexing-based wireless cellular systems. The use of conventional sounding schemes may suffer from interference from other sectors and also require large signaling overhead. To reduce the sounding interference near the sector boundary as well as the signaling overhead, we allocate the sounding physical resource unit (PRU) by exploiting the channel correlation in the frequency domain. The proposed scheme transmits the sounding signal through the PRUs which are less correlated to each other, significantly reducing the signaling overhead. The whole channel information can be extracted from the sounding PRUs by means of minimum-mean-square-error estimation. Finally, the performance of the proposed sounding scheme is verified by computer simulation, showing remarkable performance improvement over conventional schemes in the presence of channel correlation, while significantly reducing the signaling overhead.