Frequency-Domain Response Based Timing Synchronization: A Near Optimal Sampling Phase Criterion for TDS-OFDM

TL;DR

This paper introduces a frequency-domain response-based near optimal sampling phase criterion for TDS-OFDM systems, improving timing synchronization by addressing sampling phase offset effects on BER, especially over multipath channels.

Contribution

It proposes a novel frequency-domain response-based sampling phase estimation criterion that outperforms conventional methods in TDS-OFDM systems under various channel conditions.

Findings

The proposed criterion achieves lower BER in simulations.

It performs well over multipath channels with channel coding.

Outperforms traditional symbol timing recovery methods.

Abstract

In time-domain synchronous OFDM (TDS-OFDM) system for digital television terrestrial multimedia broadcasting (DTMB) standard, the baseband OFDM signal is upsampled and shaping filtered by square root raised cosine (SRRC) filter before digital-to-analog converter (DAC). Much of the work in the area of timing synchronization for TDS-OFDM focuses on frame synchronization and sampling clock frequency offset recovery, which does not consider the sampling clock phase offset due to the upsampling and SRRC filter. This paper evaluates the bit-error-rate (BER) effect of sampling clock phase offset in TDS-OFDM system. First, we provide the BER for M-order quadrature amplitude modulation (M-QAM) in uncoded TDS-OFDM system. Second, under the condition of the optimal BER criterion and additive white Gaussian noise (AWGN) channel, we propose a near optimal sampling phase estimation criterion based on frequency-domain response. Simulations demonstrate that the proposed criterion also has good performance in actual TDS-OFDM system with channel coding over multipath channels, and it is superior to the conventional symbol timing recovery methods for TDS-OFDM system.