Programmable DC Power Supply for Remote Radio Cable Loss Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cellular base stations face significant power loss when delivering DC power to remote radio heads located at the top of towers, due to long coaxial cables, which degrades signal quality and increases operational costs.
Innovation Solution
A programmable power supply adjusts the voltage level of the DC power signal based on current and cable resistance to maintain a substantially constant voltage at the remote radio head, reducing power loss by optimizing the voltage drop along the power cable.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If DC power is delivered over long coaxial cables to remote radio heads at the top of towers, then the radio can be positioned at the top for improved signal quality and coverage, but significant power loss occurs in the cables
Solution Approach 1:
The patent changes the voltage parameter of the DC power signal from conventional levels (e.g., 48V) to elevated levels (e.g., 80V, 100V, or higher) to reduce current and thereby reduce I²R power losses in the coaxial cables. This parameter change allows power to be delivered efficiently over the long cable distances required to reach remote radio heads at the top of towers while maintaining signal quality.
2Loss of energy
If higher voltage is used to reduce power loss in the power cable, then power loss is reduced, but the voltage may exceed the maximum voltage rating of the radio equipment
Solution Approach 1:
The patent segments the power delivery system into two distinct functional sections: (1) a high-voltage power transmission section using elevated voltage to minimize power losses in the coaxial cable, and (2) a voltage conversion section at the remote radio head that steps down the high voltage to the safe operating voltage level for the radio equipment. This segmentation allows the system to benefit from high-voltage efficient power transmission while protecting the sensitive radio equipment through localized voltage conversion.
Solution Approach 2:
The patent introduces a voltage conversion device (such as a DC-DC converter or transformer) as an intermediary component at the remote radio head. This intermediary converts the elevated transmission voltage to the appropriate operating voltage for the radio equipment, acting as a buffer that allows high-voltage power delivery without exposing the radio equipment to damaging voltage levels.
3Object-affected harmful factors
If conventional voltage levels are used to power remote radio heads, then equipment safety is maintained, but larger diameter cables are required to reduce resistance and power loss
Solution Approach 1:
The patent changes the voltage parameter from conventional levels to elevated levels, which inversely changes the required cable characteristics. By operating at higher voltage, the system can use smaller diameter coaxial cables with higher characteristic impedances while still delivering power efficiently and safely (through voltage conversion at the remote end). This parameter change flips the traditional relationship where high power required thick cables.
4Reliability
If the radio is located at the bottom of the tower in the equipment enclosure, then power delivery is simple and reliable, but signal transmission loss over the coaxial cable degrades signal quality
Solution Approach 1:
The patent segments the radio system into a baseband unit (BBU) located at the bottom of the tower in the equipment enclosure and a remote radio head (RRH) located at the top of the tower. The BBU handles power management and baseband processing, while the RRH handles RF transmission. This segmentation allows the radio frequency functions to be positioned optimally for signal quality while power delivery is managed separately through the high-voltage DC power delivery system.
Solution Approach 2:
The patent introduces a high-voltage DC power delivery system as an intermediary that enables the separation of the radio from the power supply location. This intermediary power delivery system allows the radio to be positioned remotely at the top of the tower for optimal signal transmission while power is delivered efficiently through the coaxial cable using elevated voltage to overcome the distance-related power losses.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach minimizes power loss and reduces operational costs by maintaining a constant voltage at the remote radio head, allowing for the use of smaller diameter cables and longer cabling connections, thereby improving signal quality and reducing capital expenditures.
Implementation Method 1
A voltage level of the DC power signal that is output from the power supply is adjusted so that the DC power signal at a radio end of the power cable that is remote from the power supply has a substantially constant voltage notwithstanding variation in a current level of the DC power signal
Data Source
AI summary
Methods of powering a radio that is mounted on a tower of a cellular base station are provided in which a direct current (“DC”) power signal is provided to the radio over a power cable and a voltage level of the output of the power supply is adjusted so as to provide a substantially constant voltage at a first end of the power cable that is remote from the power supply. Related cellular base stations and programmable power supplies are also provided.