Parametric Channel Estimation by Exploiting Hopping Pilots in Uplink   OFDMA
  This paper proposes a parametric channel estimation algorithm applicable to uplink of OFDMA systems with pseudo-random subchannelization. It exploits the hopping pilots to facilitate ESPRIT to estimate the delay subspace of the multipath fading channel, and utilizes the global pilot tones to interpolate on data subcarriers. Hence, it outperforms the traditional local channel interpolators considerably. 
Xiaochuan Zhao (1), Tao Peng (1) and Wenbo Wang (1) ((1) Beijing   University of Posts and Telecommunications, Beijing, China)