Design and Implementation of Configurable MODEM for Inter-Satellite Link Transceiver

Nowadays, satellite constellations have a special capability to provide unique and new applications such as cellular telephone networks, stable and high-speed internet over satellite, and superior imaging capabilities over large coverage areas. A constellation of satellites could cover a large area of the earth with a permanent communication link. Through a communication session between the ground stations and any satellite of the constellation, the authorized ground station has the privilege of communicating with all satellites of the constellation. Higher data rates are essential for the link between the ground station and the satellite during a limited communication session. However, low data rates are only required in between the satellite constellation links as they can exchange data anytime. Configurable quadrature phase-shift keying (QPSK) high-performance modem design is presented in this paper in order to be utilized for any type of communication links and data rate according to the mission of the satellite. The modem is designed in a way that can support both low and high data rates depending on the desired usage. MATLAB results show the ability of the proposed design to exchange data with high and stable performance over both the inter-satellite and satellite-to-ground station links. Furthermore, the design is successfully implemented on the Kintex-7 chip with the required analog to digital converter (ADC) and digital to analog converter (DAC) interfaces to construct the whole system-on-chip. High clock speed and low resource utilization are achieved and presented after the complete implementation. The results prove the ability of the proposed design to be utilized for the required satellite links based on the introduced link budget analysis. This paper will demonstrate the modeling of the design on MATLAB, and the implementation of the design on the Field Programmable Gate Array (FPGA). Finally, the performance of the integrated design on the hardware shows its reliability for achieving the space mission requirements.