OFDM Channel Estimation Based on Impulse Response Decimation: Analysis and Novel Algorithms

• Published in: Ieee Transactions On Communications (ISSN: 0090-6778), vol. 60, num. 7, p. 1996-2008
• Piscataway: Institute of Electrical and Electronics Engineers, 2012

In this paper, OFDM data-aided channel estimation based on the decimation of the Channel Impulse Response (CIR) through the selection of the Most Significant Samples (MSS) is addressed. Our aim is to approach the Minimum Mean Square Error (MMSE) channel estimation performance, while avoiding the need for a-priori knowledge of channel statistics (KCS). The optimal set of samples is defined in the instantaneous and average senses. We derive lower bounds on the estimation mean-square error (MSE) performance for any MSS selection strategy. We show how MSS-based channel estimation can approach these MSE lower bounds. We introduce novel MSS strategies oriented towards instantaneous decimation (Instantaneous Energy Selection - IES), and windowed decimation (Average Energy Selection - AES). We also consider decimation via Threshold Crossing Selection (TCS), which we characterize analytically, to derive the optimum threshold in the minimum MSE sense. We also propose a sub-optimal method for threshold setting that does not require KCS. Finally, we provide numerical results in terms of both MSE estimation performance and Bit Error Rate (BER) of a coded OFDM system using the proposed channel estimators, to show that they indeed approach MMSE performance.

Keywords: OFDM ; channel estimation ; minimum mean square error (MMSE) ; impulse response ; pilot tone ; DVB ; threshold selection

Reference

• EPFL-ARTICLE-184547
• doi:10.1109/Tcomm.2012.051012.090606
• View record in Web of Science

Record created on 2013-02-27, modified on 2017-05-12