Parametric Channel Estimation for Pseudo-Random User-Allocation in Uplink OFDMA

Abstract — In this work, we present an algorithm for parametric estimation of a wireless channel for OFDMA transmission, tailored to the pseudo-random “tile ” allocation pattern prevalent in multi-user allocation schemes 1. Such tile allocations are usually common in the uplink where a tile is usually a small number of adjacent data subcarriers with a few pilot subcarriers. The algorithm estimates the delay subspace of the parametric channel description, and shows robustness for high RMS delay-spread channels. The estimator error convergence performance improves with increase in the channel Doppler frequency. Although the proposed algorithm requires more intensive computation than straight-forward intra-tile linear interpolation, it offers a greatly enhanced Bit-Error-Rate (BER) performance. In mobile channel environments, the need for numerous re-transmissions is therefore decreased, making this algorithm suitable for low BER applications such as video and data. I