Improved Channel Estimation Methods based on PN sequence for TDS-OFDM

TL;DR

This paper proposes improved channel estimation methods for TDS-OFDM using PN sequences, achieving near-optimal accuracy by reducing estimation errors through novel estimators that approach the Cramer-Rao bound.

Contribution

It introduces new estimators based on PN sequence cross-correlation that outperform existing methods and closely approach the theoretical Cramer-Rao bound.

Findings

New estimators significantly reduce estimation error floor.

Proposed methods approach the Cramer-Rao bound.

Simulations confirm improved accuracy over traditional estimators.

Abstract

An accurate channel estimation is crucial for the novel time domain synchronous orthogonal frequency-division multiplexing (TDS-OFDM) scheme in which pseudo noise (PN) sequences serve as both guard intervals (GI) for OFDM data symbols and training sequences for synchronization/channel estimation. This paper studies the channel estimation method based on the cross-correlation of PN sequences. A theoretical analysis of this estimator is conducted and several improved estimators are then proposed to reduce the estimation error floor encountered by the PN-correlation-based estimator. It is shown through mathematical derivations and simulations that the new estimators approach or even achieve the Cramer-Rao bound.