A Cell Detection Technique for Downlink Channel in Underwater Multicell Networks

The concept of frequency reuse has been considered for underwater acoustic multicell networks due to the limited available bandwidth of acoustic channels. In the multicell network, an underwater equipment (UE) needs to detect the identity of the underwater base station (UBS) and synchronize to the serving UBS, in Doppler environments. In this paper, we propose a preamble based on linear frequency modulation (LFM) to detect the identity of UBS at the physical layer under the effect of Doppler shift. An ambiguity function (AF) of the proposed LFM-based preamble is derived to investigate its correlation property under the effect of Doppler shift.