## 1 Introduction
In view of the fact that when the vehicle cruises at hypersonic speed in the NS, a plasma sheath is generated, which seriously affects the transmission performance of communication signals. [PERSON] (2016) recommended methodologies and enabling technologies based on NASA's fundamental architectural concept for its future space communications and navigation (SCaN) framework and space relay capability requirements for 2025-2040, which could provide design references for current and future ICNT architectures [21]. [PERSON] et al. (2016) used the finite-difference time-domain (FDTD) method to analyze the transmission characteristics of the terahertz band in a non-uniform plasma sheath, then studied the influence of the steepness of the electron density distribution and the changes in the peak point on its transmission performance [22], providing theoretical support for the signal transmission of ICNT in the NS. [PERSON] (2017) proposed using an optical communication system for deep space navigation and was committed to making the system meet the navigation requirements of the mission, so that it could serve only as a backup for emergency communication and navigation. This provides a reference example for the multi-source fusion mode of ICNT [23]. [PERSON] et al. (2017) explored the integrated design architecture of TT&C and communication from the aspect of network coverage. They designed a three-layer architecture of the space-air-ground integrated TT&C and communication network with comprehensive coverage and flexible networking. However, the navigation service was not taken into consideration. Nevertheless, it can still provide a reference for the information transmission of ICNT [24]. [PERSON] et al. (2019), from the perspective between the navigation payload and the signal design, analyzed the degradation effect of the constant envelope signal in the nonlinear power amplifier. This research provides a theoretical basis for the compatibility design of NS navigation signals in hardware implementation [25]. [PERSON] (2020) pointed out that to achieve the goal of increasing future space applications by an order of magnitude, higher RF bands and optical communication technologies are required to avoid spectrum congestion, and better channel coding and modulation methods are needed to make full use of the limited power and spectrum resources. This is in line with the connotation of the signal design technology of ICNT [26]. [PERSON] et al. (2023) introduced a tutorial on the TT&C for spacecraft and satellite missions. They also provided supplementary information about emerging TT&C technologies and the standardized framework, which offers fundamental research support for the signal design of future ICNT [27]. [PERSON] et al. (2024) explored the role of NS communication in the space-air-ground-sea integrated network (SAGSIN), pointed out that the NS platform can provide low-latency and wide-coverage signal relay services for navigation and communication, and also proposed the design direction of navigation and communication signals based on the reconfigurable multiple-input multiple-output (MIMO) technology [28], but this design did not incorporate TT&C services. [PERSON] et al. (2023, 2025) proposed a modulation method based on two-dimensional orthogonal time-frequency space (OTFS) and non-coherent orthogonal time-frequency space modulation. This type of modulation is expected to solve the multipath problem of NS by transforming the fading problem encountered in the time-frequency domain into time-invariant fading in the delay-Doppler (DD) domain [29; 30]. Although the above studies have proposed numerous alternative reference schemes, at present, there is no complete design architecture and corresponding solution for the ICNT signals in the NS within the K/Ka frequency bands and even higher frequency bands.