Delay-Doppler Block Division Multiplexing: An Integrated Navigation and Communication Waveform for LEO PNT  
[PERSON]  
1 College of Electronic Science and Technology, National University of Defense Technology, Changsha 410073, China; [EMAIL_ADDRESS] (D.F. ); [EMAIL_ADDRESS] (H.L. ); [EMAIL_ADDRESS] (I.P. ); [EMAIL_ADDRESS] (G.O. ); [EMAIL_ADDRESS] (S.W.) 12 Key Laboratory of Satellite Navigation Technology, National University of Defense Technology, Changsha 410073, China 2  
[PERSON]  
1 College of Electronic Science and Technology, National University of Defense Technology, Changsha 410073, China; [EMAIL_ADDRESS] (D.F. ); [EMAIL_ADDRESS] (H.L. ); [EMAIL_ADDRESS] (I.P. ); [EMAIL_ADDRESS] (G.O. ); [EMAIL_ADDRESS] (S.W.) 12 Key Laboratory of Satellite Navigation Technology, National University of Defense Technology, Changsha 410073, China 2  
[PERSON]  
1 College of Electronic Science and Technology, National University of Defense Technology, Changsha 410073, China; [EMAIL_ADDRESS] (D.F. ); [EMAIL_ADDRESS] (H.L. ); [EMAIL_ADDRESS] (I.P. ); [EMAIL_ADDRESS] (G.O. ); [EMAIL_ADDRESS] (S.W.) 12 Key Laboratory of Satellite Navigation Technology, National University of Defense Technology, Changsha 410073, China 2  
[PERSON]  
1 College of Electronic Science and Technology, National University of Defense Technology, Changsha 410073, China; [EMAIL_ADDRESS] (D.F. ); [EMAIL_ADDRESS] (H.L. ); [EMAIL_ADDRESS] (I.P. ); [EMAIL_ADDRESS] (G.O. ); [EMAIL_ADDRESS] (S.W.) 12 Key Laboratory of Satellite Navigation Technology, National University of Defense Technology, Changsha 410073, China 2  
[PERSON]  
1 College of Electronic Science and Technology, National University of Defense Technology, Changsha 410073, China; [EMAIL_ADDRESS] (I.P. ); [EMAIL_ADDRESS] (H.L. ); [EMAIL_ADDRESS] (I.P. ); [EMAIL_ADDRESS] (G.O. ); [EMAIL_ADDRESS] (S.W.) 12 Key Laboratory of Satellite Navigation Technology, National University of Defense Technology, Changsha 410073, China 2  
[PERSON]  
1 College of Electronic Science and Technology, National University of Defense Technology, Changsha 410073, China; [EMAIL_ADDRESS] (H.L. ); [EMAIL_ADDRESS] (I.P. ); [EMAIL_ADDRESS] (G.O. ); [EMAIL_ADDRESS] (S.W.) 12 Key Laboratory of Satellite Navigation Technology, National University of Defense Technology, Changsha 410073, China 2  
Footnote 1: email: {1220 signals in environments characterized by deep attenuation and interference, fostering the development of integrated navigation and communication (INAC) technology based on broadband modulation. An INAC system can effectively reduce the costs associated with constellation construction; thus, the implementation of navigation based on broadband modulation has become an important research area [7]. Orthogonal frequency division multiplexing (OFDM) offers high spectral efficiency, effective multipath mitigation, and a large mean square bandwidth [8; 9], making it widely used in wireless communication and INAC systems. The long-term evolution (LTE) system independently performs positioning using a positioning reference signal (PRS) based on OFDM, which is located in the positioning subframes, and the new radio (NR) further optimizes the PRS for better positioning performance [10; 11]. However, there are severe near-far effects between the positioning signals from different base stations, which make the signals from far base stations more difficult to receive, resulting in a positioning accuracy of a few tens of meters. This is not enough for the high-precision positioning of future applications [12; 13]. To mitigate the near-far effects, [PERSON] proposed a multi-scale non-orthogonal multiple access (MS-NOMA) scheme [14]. In this scheme, the navigation signal is modulated using OFDM, and employs different pseudo-random noise (PRN) code sequences across various subcarriers to allocate resources to multiple positioning users. However, it imposes a limitation on the number of positioning users. [PERSON] proposed a time code division-OFDM (TC-OFDM) signal [15; 16].