Frequency-Domain Oversampling for Zero-Padded OFDM in Underwater Acoustic Communications

Although time-domain oversampling of the received baseband signal is common for single-carrier transmissions, the counterpart of frequency-domain oversampling is rarely used for multicarrier transmissions. In this paper, we explore frequencydomain oversampling to improve the system performance of zero-padded OFDM transmissions over underwater acoustic channels with large Doppler spread. We use a signal design that enables separate sparse channel estimation and data detection, rendering a low complexity receiver. Based on both simulation and experimental results, we observe that the receiver with frequency-domain oversampling outperforms the conventional one considerably in channels with moderate and large Doppler spreads, and the gain increases as the Doppler spread increases. Although a raised-cosine pulse-shaping window can be used to improve the system performance relative to a rectangular window at the expense of data rate reduction, the performance gain is much less than that brou...

• Type: Journal
• Year: 2010
• Where: GLOBECOM
• Authors: Zhaohui Wang, Shengli Zhou, Georgios B. Giannakis, Christian R. Berger, Jie Huang
• Keywords: Communications, Frequency-domain, GLOBECOM 2010, Large Doppler, Oversampling