Shenzhen Huashi Digital Technology Co., Ltd.: Addressing 5G Interference and Safeguarding C-Band Satellite Communications
White Paper Release
Engineering Department – Li Wilson, Senior Communications System Engineer at Huashi
Release Date: June 2019 (Revised: December 2019)
Introduction
Since the beginning of 2019, mobile network operators (MNOs) worldwide have initiated testing and large-scale deployment of 5G cellular base stations, particularly in China and many other countries. However, this process poses a significant challenge: the spectrum used by 5G macrocells overlaps with the extended C-band (3.4-3.7 GHz) that has long been used for satellite communication services. In some countries and regions, the 5G spectrum even partially or fully overlaps with the standard C-band (3.7-4.2 GHz), which is also widely used for fixed satellite services (FSS).
Shenzhen Huashi Digital Technology Co., Ltd., as a key player in C-band satellite communications in the Asia-Pacific region, is fully aware of the impact this challenge will have on satellite users in the coming years. To address the potential interference from 5G deployments and better serve our customers, Huashi, leveraging its 30 years of experience in meeting satellite user needs, has closely collaborated with leading industry suppliers to introduce a new microwave bandpass filter (BPF). This BPF is designed to be installed on C-band receiving antennas to effectively suppress interference signals from adjacent 5G base stations, ensuring the stability and reliability of satellite communications.
Types of 5G Interference and Countermeasures
In satellite receiving systems, traditional low-noise block downconverters (LNBs) have limited frequency selection capabilities, capable of receiving, amplifying, and downconverting signals within the 3.0-4.5 GHz range. However, with the deployment of 5G New Radio (NR) carriers in the 3.4-3.6 GHz band, this frequency band falls directly within the input frequency range of LNBs, potentially causing three main types of interference to satellite receiving systems:
Co-channel interference: Satellite carriers located within the 5G carrier frequency band experience direct interference, resulting in degraded signal quality.
Adjacent-channel interference: Satellite carriers near the 5G carrier frequency band are degraded by spectrum regeneration and out-of-band spurious emissions from 5G transmissions, affecting reception performance.
LNB saturation interference: High-power 5G carriers may drive the LNB operating point into saturation or nonlinear regions, causing distortion or even power loss for satellite carriers received across the entire C-band.
To effectively address these interferences, the new microwave bandpass filter (BPF) introduced by Huashi Digital Technology has become a key solution. Through precise frequency selection and filtering technology, the BPF can effectively suppress 5G interference signals and protect satellite receiving systems from interference.
Field Testing and Customer Feedback
This white paper provides a detailed introduction to the functions of the BPF and its performance in field testing and customer environments. Through a series of rigorous tests and validations, we have demonstrated the BPF's exceptional performance in suppressing 5G interference. Customer feedback has also positively affirmed the effectiveness and reliability of our product.
Conclusion
As a leading enterprise in the satellite communications field, Shenzhen Huashi Digital Technology Co., Ltd. is always committed to providing customers with the highest quality products and services. In the face of the challenges posed by 5G, we will continue to increase our research and development investments, continuously innovate and improve our product solutions, ensuring that our customers can enjoy stable and reliable satellite communication services.
