mMIMO Beam Coverage Control in Antenna Power Saving Mode
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Solution Overview
Problem
MIMO networks face interference issues due to power saving modes that alter radiation patterns, causing beams to overshoot intended coverage areas and interfere with neighboring cellular sites.
Innovation Solution
Adjust beam angles of depression and reduce the number of synchronization signal block transmissions to contain beams within intended areas, using methods such as increasing the electrical down tilt and disabling specific rows or columns of antennas in mMIMO arrays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If antenna branches are deactivated to save power, then power consumption is reduced, but interference with nearby cellular sites increases
Solution Approach 1:
The patent changes the beam angle parameter when deactivating antenna branches. By increasing the beam angle of depression, the radiation pattern is modified to direct energy more downward, reducing horizontal spread and thus interference with nearby cells while maintaining power savings from reduced antenna usage.
Solution Approach 2:
The system dynamically adjusts the beam angle based on the operational state of antenna branches. When antennas are deactivated, the beam angle is increased to compensate for the changed radiation pattern, creating an adaptive system that maintains appropriate coverage while reducing interference.
2Use of energy by stationary object
If the number of transmit antennas is reduced, then power consumption decreases, but the radiation pattern is altered causing interference
Solution Approach 1:
The patent modifies the beam angle parameter to compensate for the reduced number of active antennas. By increasing the beam angle of depression, the system maintains a more focused radiation pattern that reduces interference with nearby cellular sites while still providing necessary coverage.
3Object-generated harmful factors
If beam angle of depression is increased to reduce interference, then interference is reduced, but coverage area is reduced
Solution Approach 1:
The system uses a partial set of antenna branches (not all) and combines this with an adjusted beam angle. This partial action approach allows the system to achieve both reduced interference through fewer antennas and controlled coverage through the adjusted beam angle, balancing the two requirements.
Data Source
AI summary
In order to reduce power consumption, an access node may turn off transmissions from one or more rows or columns of antennas in a mMIMO array. To help prevent the beam from overshooting (i.e., going beyond) an intended area of coverage when the access node turns off transmission by one or more rows, the access node also increases the electrical down tilt of the beam (i.e., angle of depression) to help contain the beam within its intended area of coverage. To help prevent problems with SSB beam selection and/or beam switching, when the access node turns off transmission by one or more columns, the access node reduces the number of SSB beams that are transmitted while sweeping SSBs over the sector thereby reducing the overlap of the (now) wider SSB beams.