PIM Cancellation Algorithm Dynamic Activation
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Solution Overview
Problem
Passive InterModulation (PIM) caused by non-linear passive components in telecom systems leads to signal desensitization and throughput loss in cellular base stations, especially with the deployment of multi-band base stations, as existing PIM cancellation algorithms struggle with accurate decision-making when PIM levels are close to the noise floor, leading to potential over-cancellation or under-cancellation issues.
Innovation Solution
The development of a method to estimate the real-time PIM slope of passive components using live traffic, allowing for accurate determination of when to turn on or off the PIM cancellation algorithm, thereby improving signal decoding and reducing throughput loss by characterizing the PIM source's slope without disrupting normal operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If PIM cancellation algorithm is continuously activated, then signal quality improves, but system complexity and energy consumption increase
Solution Approach 1:
The PIM cancellation algorithm is implemented with dynamic activation based on real-time PIM level detection. The system continuously monitors PIM levels and adaptively switches the cancellation algorithm on or off, transforming a static continuous operation system into a dynamic one that adjusts to actual signal conditions, thereby reducing unnecessary complexity and energy consumption while maintaining signal quality when needed.
Solution Approach 2:
The system changes the operational parameter (activation state) of the PIM cancellation algorithm based on detected PIM levels. When PIM levels exceed a threshold, the algorithm is activated; when levels are acceptable, it is deactivated. This parameter-based control optimizes the trade-off between signal quality and system complexity by only engaging the complex cancellation function when actually required.
2Reliability
If PIM cancellation algorithm is activated, then signal desensitization is reduced, but throughput loss may occur due to inaccurate activation decisions
Solution Approach 1:
The system implements a feedback mechanism where PIM levels are continuously measured and used to control the activation of the cancellation algorithm. This closed-loop feedback ensures the algorithm is activated only when PIM interference actually degrades signal quality, avoiding unnecessary throughput loss from unwarranted algorithm activation while ensuring reliability when PIM levels are problematic.
Solution Approach 2:
The patent replaces complex mechanical or hardware-based PIM filtering systems with a software-based algorithmic approach that can be dynamically controlled. This substitution allows for more precise control over when cancellation is applied, using computational methods rather than fixed hardware configurations, thereby optimizing the balance between reliability and throughput.
3Measurement precision
If PIM measurement is performed using standardized two-tone method, then PIM levels can be measured, but normal base station operation is disrupted
Solution Approach 1:
The base station performs PIM measurements using its own transmitted signals and received interference during normal operation, rather than requiring external two-tone test equipment. The system utilizes its existing transmit carriers and measures the resulting intermodulation products in the receive path, allowing self-diagnosis of PIM levels without external intervention or service disruption.
Solution Approach 2:
The PIM measurement process is integrated into the continuous normal operation of the base station. Instead of periodic external testing that interrupts service, the system continuously measures PIM levels using live traffic and operational signals, maintaining both measurement capability and uninterrupted productive operation simultaneously.
Data Source
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AI summary
An apparatus is disclosed, comprising means for determining a noise floor for a radio frequency (RF) system. The apparatus may also comprise means for determining a Passive InterModulation (PIM) value of a component of the RF system contributing as a source of PIM; determining that a passive intermodulation (PIM) cancellation system should be enabled if the PIM value is above a predetermined threshold from the noise floor. The apparatus may also comprise means for determining that the PIM cancellation system should be disabled if the PIM value is at or below the predetermined threshold.