## 1 Introduction  
Compared to geostationary Earth orbit (GEO) satellites, low Earth orbit (LEO) satellites, with their unique constellation and signal advantages, have gradually attracted attention and favor in the global satellite navigation field. LEO satellite systems offer advantages such as low transmission loss, short transmission delay, flexible satellite launches, and global coverage, including the polar regions [1; 2; 3]. A typical processing flow for a LEO satellite broadcast signal reception terminal is shown in Figure 1[4]. The terminal processes the signal through radio frequency (RF) processing, analog-to-digital conversion (ADC), narrowband interference suppression, digital beamforming, filtering, extraction, and truncation, followed by information processing such as signal capture, tracking, timing synchronization, frame synchronization, data demodulation, message decoding, and positioning operations. This enables signal reception and processing in complex electromagnetic interference environments. Beamforming methods are divided into analog beamforming (ABF) and digital beamforming (DBF), and their differences mainly lie in the following aspects:  
(1) Signal Processing:  
ABF: In ABF, signals are weighted and combined through analog circuits, typically using analog phase control and circuitry to control the signals of each antenna element. It relies on analog hardware (such as phase shifters, adders, etc.) to adjust the phase and amplitude of individual signals, thereby forming a target beam. DBF: In DBF, the received signals are first converted into digital signals through an analog-to-digital converter (ADC) and then processed in the digital domain. After digital processing, the phase and amplitude of each signal can be controlled through algorithms. This allows signal weighting, phase control, beam adjustment, and other processes to be fully implemented in the digital domain. (2) Flexibility:  
ABF: The flexibility of ABF is relatively low because hardware (such as phase shifters and adders) limits the precision and range of beam adjustment. Generally, it is only suitable for forming fixed beams and simple beam control. DBF: DBF offers greater flexibility because all processing is done in the digital domain, enabling more precise beam adjustment, simultaneous generation of multiple beams, and more complex signal processing. (3) Performance:  
ABF: The performance of ABF is limited by hardware accuracy. Due to the non-ideal nature of analog circuits, there may be issues such as low beamforming precision and large sidelobes. Figure 1: Processing flow diagram of a typical LEO satellite broadcast signal reception terminal. DBF: DBF can achieve higher beamforming precision and lower sidelobe performance. It usually provides better interference suppression and adaptive capabilities, which significantly improve receiver performance. (4) Implementation of Resources:  
ABF: ABF typically requires fewer digital hardware resources, mainly relying on analog hardware for signal processing. As a result, the system is relatively simple, with lower power consumption, but it is difficult to implement complex adaptive beamforming. DBF: DBF requires stronger digital processing capabilities and is typically equipped with high-performance digital signal processors (DSPs) or FPGAs. While the hardware cost and power consumption are higher, DBF can implement more complex functions. (5) Cost and Complexity:  
ABF: Compared to DBF, ABF has lower cost and complexity. It is suitable for simpler applications, but it may lack flexibility in applications requiring high precision and complex beam control. DBF: DBF systems are usually more expensive, with higher hardware complexity, but they offer more powerful functionalities and higher performance, especially in applications requiring precise control and complex beamforming.