Channel Sounding for Multi-Sector Cooperative Beamforming in TDD-OFDM Wireless Systems

In this paper, we consider channel sounding for multi-sector cooperative beamforming in othogonal frequency division multiplexing-based wireless cellular systems. To reduce sounding interference and signaling overhead, we allocate sounding physical resource units (PRUs) by exploiting the correlation characteristics in the frequency domain. The proposed scheme transmits sounding signal through PRUs which are not highly correlated to each other, significantly reducing the sounding interference and signaling overhead. Then, the whole channel information can be extracted by means of channel estimation based on the frequency correlation (e.g., minimum-mean-square-error estimation). Simulation results show that the proposed scheme provides remarkable performance improvement over conventional schemes in the presence of channel correlation in the frequency domain.