Preamble-Based Channel Estimation for CP-OFDM and OFDM/OQAM Systems: A Comparative Study

TL;DR

This paper compares preamble-based LS channel estimation methods for CP-OFDM and OFDM/OQAM systems, analyzing optimal preamble design and demonstrating that OFDM/OQAM performs at least as well as CP-OFDM under similar power conditions.

Contribution

It provides a comprehensive comparison of preamble-based channel estimation in CP-OFDM and OFDM/OQAM, including optimal preamble construction and performance evaluation.

Findings

OFDM/OQAM with sparse preambles performs at least as well as CP-OFDM.

Optimal preambles are constructed in both frequency and time domains.

Simulations verify the theoretical analysis and performance comparisons.

Abstract

In this paper, preamble-based least squares (LS) channel estimation in OFDM systems of the QAM and offset QAM (OQAM) types is considered, in both the frequency and the time domains. The construction of optimal (in the mean squared error (MSE) sense) preambles is investigated, for both the cases of full (all tones carrying pilot symbols) and sparse (a subset of pilot tones, surrounded by nulls or data) preambles. The two OFDM systems are compared for the same transmit power, which, for cyclic prefix (CP) based OFDM/QAM, also includes the power spent for CP transmission. OFDM/OQAM, with a sparse preamble consisting of equipowered and equispaced pilots embedded in zeros, turns out to perform at least as well as CP-OFDM. Simulations results are presented that verify the analysis.