PIM Cancellation Adapt Architecture for Uplink IF Interference
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Solution Overview
Problem
Passive intermodulation (PIM) interference is a growing issue in cellular networks, particularly in Frequency Division Duplex (FDD) systems, causing interference that reduces receiver sensitivity and affects both the cell creating it and nearby receivers, with traditional frequency planning becoming impractical due to spectrum scarcity and antenna sharing schemes.
Innovation Solution
A PIM cancellation adapt architecture in the uplink multi-carrier intermediate frequency (IF) domain that processes data to generate PIM interference models, compensating for interference by concatenating frequency-shifted captured data and models using a double buffer structure with reduced hardware cost and adapt speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional frequency planning is used to avoid PIM interference, then PIM interference is reduced, but spectrum utilization becomes impractical due to spectrum scarcity and antenna sharing schemes
Solution Approach 1:
The patent converts the harmful PIM interference into a beneficial signal by using the interference itself as training data to adapt the PIM model. The PIM model processes the captured uplink data through frequency shifting and concatenation with frequency-shifted PIM models to generate corrected signals, effectively turning the interference problem into a self-calibrating mechanism that improves receiver sensitivity without requiring traditional frequency planning
2Reliability
If PIM cancellation is implemented in the uplink multi-carrier IF domain, then receiver sensitivity is improved, but hardware complexity increases
Solution Approach 1:
The patent performs preliminary frequency shifting of the captured uplink data and PIM models before concatenation. This preliminary action prepares the data in advance for the PIM cancellation process, enabling the system to achieve effective PIM cancellation in the uplink multi-carrier IF domain while managing hardware requirements through efficient signal processing sequences
Solution Approach 2:
The patent introduces an intermediary PIM model that acts as a mediator between the captured uplink data and the final corrected signal. The PIM model processes the data through frequency shifting and concatenation operations, serving as a computational bridge that enables PIM cancellation without requiring direct complex hardware modifications
3Measurement precision
If frequency shifting is applied to captured data and PIM models, then PIM interference compensation is improved, but processing time increases
Solution Approach 1:
The patent applies frequency shifting in a periodic manner during the PIM model adaptation process. The captured data and PIM models are frequency shifted at specific intervals and then concatenated, creating a periodic processing pattern that achieves effective PIM compensation while managing computational load through rhythmic, structured operations rather than continuous processing
Data Source
AI summary
Embodiments herein describe a circuit including a passive intermodulation (PIM) model circuit configured to process first data to generate a PIM interference model output to be concatenated with second data, the second data including a first carrier frequency and a second carrier frequency, and the circuit further including a PIM model adapt circuit configured to receive frequency shifted captured data and frequency shifted PIM models to generate updated values to compensate for PIM interference after the PIM interference model output is concatenated with the second data.