Sub-Optimum Pilot Placement for Chunk-based OFDMA Uplink: Consecutive Chunks Scenario

Channel estimation for the chunk-based OFDMA uplink communications is based on the non-ideal interpolation schemes, e.g., polynomial interpolation. The channel estimation performance depends on the modeling mismatch, pilot pattern and the signal-to-noise ratio. In this paper, we first investigate the channel estimation performance for the polynomial interpolation, which takes into account the impact of modeling mismatch and thermal noise. This is then followed by a novel sub- optimum pilot-placement scheme, which can considerably improve channel estimation and overall system performance for the consecutive chunks scenario, i.e., each user has several consecutive chunks along the frequency direction.