The inter-satellite laser interferometer, which functions as a high-performance displacement sensor, will be used in forthcoming space-based gravitational wave detection missions. The readout of these interferometers is typically performed by phasemeters based on all-digital phase-locked loops (ADPLLs) implemented in FPGAs. This paper proposes a feasible loop parameter design workflow and a comprehensive noise model, providing guidelines for designing and optimizing an ADPLL to meet specified bandwidth and precision requirements. The validity of our analysis is demonstrated through numerical performance measurements based on the modified digital splitting test.

The detection of space-based gravitational waves imposes stringent requirements on inter-satellite absolute distance measurement and communication capabilities. To address the issues of high resource consumption and platform complexity associated with the traditional approach of separating ranging system and communication system, this paper proposes an integrated ranging and communication scheme based on a one-way link. Utilizing pseudo-random noise (PRN) code modulation, the scheme achieves high-precision inter-satellite absolute distance measurement while simultaneously supporting data transmission on the same carrier. To validate the feasibility of the scheme, a ground-based proof-of-principle system was developed, integrating core electronic processing modules and an optical link. Experimental results demonstrate that the integrated system operates stably under laboratory conditions, achieving a ranging accuracy better than 1 cm (at a data rate of 3 Hz) while transmitting communication data at 39 kbps, fully meeting the requirements of space-based gravitational wave detection missions. Through joint electronic and optical experiments, this study confirms the effectiveness and high performance of the proposed integrated scheme, offering a streamlined and highly promising alternative for the design of inter-satellite link systems in future space-based gravitational wave detection projects.