IP Library › Granted Patent US 12,603,667
Granted Patent B2
US 12,603,667 · App. 18/556,426 · Granted Apr 14, 2026

Method and apparatus for detecting and correcting passive intermodulation (PIM)

Inventors: Zhongwen Zhu (Saint-Laurent, CA); Manoj Kopparambil Nambiar (New Westminster, CA)
Assignee: Telefonaktiebolaget LM Ericsson (publ)
H04B1/1027
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 12,603,667
App. No.
18/556,426
Granted
Apr 14, 2026
Kind
B2
Abstract

The disclosure relates to a method, apparatus and computer readable media, for detecting and correcting passive intermodulation (PIM). The method comprises receiving a radio frequency (RF) signal. The method comprises providing the RF signal to a first and a second PIM detectors. The method comprises, upon detection of PIM by at least one of the first and second PIM detectors, for which, based on a schedule, the detection of PIM is applicable at a time of detection of PIM, activating PIM correction.

Claims (35)

1 . A method for detecting and correcting passive intermodulation (PIM), comprising:

receiving a radio frequency (RF) signal;

providing the RF signal to a legacy PIM detector (PIMD) and a model-based PIM detector, wherein the model-based PIM detector comprises a features extractor which extracts features from the RF signal and feeds the features into a trained model for detection of PIM and wherein the features extracted from the RF signal comprise minimum, maximum, average, standard deviation of amplitude and frequency measurements of the RF signal, and corresponding PIM or NO-PIM expected outputs correspond to outputs from the model-based PIM detector or from the PIMD; and

upon detection of PIM by at least one of the PIMD and the model-based PIM detector, for which, based on a schedule, the detection of PIM is applicable at a time of detection of PIM, activating PIM correction.

2 . The method of claim 1 , wherein the RF signal is received by a base station through an antenna.

3 . The method of claim 2 , wherein activating PIM correction comprises correcting a new RF signal to be transmitted from the base station through the antenna.

4 . The method of claim 1 , wherein the features extracted from the RF signal, and the corresponding PIM or NO-PIM expected outputs, are collected and labeled for training the model.

5 . The method of claim 1 , further comprising receiving a new model, updated via offline training, and updating the trained model-based PIM detector with the new model.

6 . The method of claim 1 , wherein activating PIM correction comprises sending a signal to a PIM Corrector (PIMC) Controller (PIMC-C) decoupled from a PIMC Processor (PIMC-P).

7 . The method of claim 6 , wherein the PIMC-C and the PIMC-P are not collocated in a same hardware and wherein PIM correction is effected by PIMC-C and PIMC-P collectively.

8 . The method of claim 7 , wherein one PIMC-C serves a plurality of base stations.

9 . The method of claim 1 , wherein the schedule defines at least one of:

a time period when detection of PIM is applicable for the PIMD only,

a time period when detection of PIM is applicable for the model-based PIM detector only, and

a time period when detection of PIM is applicable for both the PIMD and the model-based PIM detector concurrently.

10 . An apparatus for detecting and correcting passive intermodulation (PIM) comprising processing circuits and a memory, the memory containing instructions executable by the processing circuits whereby the apparatus is operative to:

receive a radio frequency (RF) signal;

provide the RF signal to a legacy PIM detector (PIMD) and a model-based PIM detector, wherein the model-based PIM detector comprises a features extractor which extracts features from the RF signal and feeds the features into a trained model for detection of PIM and wherein the features extracted from the RF signal comprise minimum, maximum, average, standard deviation of amplitude and frequency measurements of the RF signal, and corresponding PIM or NO-PIM expected outputs correspond to outputs from the model-based PIM detector or from the PIMD; and

upon detection of PIM by at least one of the PIMD and the model-based PIM detector, for which, based on a schedule, the detection of PIM is applicable at a time of detection of PIM, activate PIM correction.

11 . The apparatus of claim 10 , wherein the RF signal is received through an antenna.

12 . The apparatus of claim 11 , wherein activating PIM correction comprises correcting a new RF signal to be transmitted through the antenna.

13 . The apparatus of claim 10 , wherein the features extracted from the RF signal, and the corresponding PIM or NO-PIM expected outputs, are collected and labeled for training the model.

14 . The apparatus of claim 10 , further operative to receive a new model, updated via offline training, and update the trained model-based PIM detector with the new model.

15 . The apparatus of claim 10 , wherein activating PIM correction comprises sending a signal to a PIM Corrector (PIMC) Controller (PIMC-C) decoupled from a PIMC Processor (PIMC-P).

16 . The apparatus of claim 15 , wherein the PIMC-C and the PIMC-P are not collocated in a same hardware and wherein PIM correction is effected by PIMC-C and PIMC-P collectively.

17 . The apparatus of claim 16 , wherein one PIMC-C serves a plurality of apparatuses.

18 . The apparatus of claim 10 , wherein the schedule defines at least one of:

a time period when detection of PIM is applicable for the PIMD only,

a time period when detection of PIM is applicable for the model-based PIM detector only, and

a time period when detection of PIM is applicable for both the PIMD and the model-based PIM detector concurrently.

19 . The apparatus of claim 10 , wherein the apparatus is a radio base station.

20 . A non-transitory computer readable media having stored thereon instructions for detecting and correcting passive intermodulation (PIM), the instructions comprising:

receiving a radio frequency (RF) signal;

providing the RF signal to a legacy PIM detector (PIMD) and a model-based PIM detector, wherein the model-based PIM detector comprises a features extractor which extracts features from the RF signal and feeds the features into a trained model for detection of PIM and wherein the features extracted from the RF signal comprise minimum, maximum, average, standard deviation of amplitude and frequency measurements of the RF signal, and corresponding PIM or NO-PIM expected outputs correspond to outputs from the model-based PIM detector or from the PIMD; and

upon detection of PIM by at least one of the PIMD and the model-based PIM detector, for which, based on a schedule, the detection of PIM is applicable at a time of detection of PIM, activating PIM correction.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 20, 2023
From: ZHU, ZHONGWEN; NAMBIAR, MANOJ KOPPARAMBIL
To: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)
Reel/Frame 065291/0933 →
Continuity (1)
Related Publication 20250088208A1 · Mar 13, 2025
References Cited (12)
US 9768812B1 · Tsui et al. · 2017 [cited by applicant]
US 10601456B2 · Tsui · 2020 [cited by applicant]
US 20180248572A1 · Ishikawa · 2018 [cited by examiner]
US 20190280732A1 · Moon · 2019 [cited by examiner]
US 20220263588A1 · Fleischer · 2022 [cited by examiner]
WO 2017072552A1 · 2015 [cited by applicant]
WO 2019203704A1 · 2019 [cited by applicant]
WO 2020208400A1 · 2020 [cited by applicant]
Christopher Stockman, “Reducing PIM on cell site towers in the 5G er” https://www.rcrwireless.com/20200724/wireless/reducing-pim-on-cell-towers-in-the-5g-era-reader-forum. [cited by applicant]
Introduction to PIM (Passive Intermodulation) https://www.anritsu.com/en-us/test-measurement/technologies/pim. [cited by applicant]
Muhammad Zeeshan et al, “Digital Cancellation of Passive Intermodulation in FDD Transceivers”, arXiv:1812.03655v1 2018 https://arxiv.org/pdf/1812.03655.pdf. [cited by applicant]
International Search Report and Written Opinion for International Patent Application No. PCT/ib2021/053743 Jan. 31, 2022, 10 pages. [cited by applicant]