Antenna Port Detection Using RSRP Filtering and SINR Thresholds

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Solution Overview

Problem

In LTE systems, user equipment (UE) faces challenges in robustly detecting the presence of a second transmit antenna port, especially when interfered by a stronger cell, which affects measurement accuracy and power consumption.

Innovation Solution

A method and user equipment (UE) that receive cell-specific reference signals on multiple antenna ports, estimate and filter reference signal received power measurements, and determine a signal-to-interference-and-noise ratio (SINR) to detect the presence of a second transmit antenna port without decoding the PBCH, enabling robust detection and potential power savings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the UE extends radio-on time to improve detection accuracy of the second transmit antenna port, then measurement precision improves, but energy consumption increases

Engineering Contradiction:
Improvedetection accuracyVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent applies partial action by performing antenna port detection only when necessary (when interference from a second transmit antenna port is suspected or detected). The UE uses RSRP measurements to determine whether a second transmit antenna port is present, and only then proceeds with full detection procedures. This avoids continuously extending radio-on time for all measurement occasions, thereby reducing energy consumption while maintaining detection accuracy when needed.

Inventive Principle:
Principle #16Partial or excessive action

2Measurement precision

If the UE performs separate channel estimation for each antenna port, then channel estimation accuracy improves, but device complexity increases

Engineering Contradiction:
Improvechannel estimation accuracyVSAvoidprocessing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the channel estimation process by first determining the presence of a second transmit antenna port using RSRP measurements, and then performing separate channel estimation for each detected antenna port. This segmentation allows the UE to avoid unnecessary separate estimations when only one antenna port is present, reducing processing complexity while maintaining estimation accuracy when multiple ports are actually being used.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by performing separate channel estimation for each antenna port only when the second transmit antenna port is detected to be present. The UE uses the determined presence information to conditionally execute the separate estimation procedures, avoiding unnecessary processing complexity when a single antenna port suffices while maintaining accuracy when multiple ports are active.

Inventive Principle:
Principle #16Partial or excessive action

3Loss of information

If the network node does not explicitly notify the UE of the antenna port mapping, then signaling overhead is reduced, but detection difficulty increases

Engineering Contradiction:
Improvesignaling overheadVSAvoiddetection difficulty
Core Design Contradiction:
Loss of informationVSDifficulty of detecting and measuring

Solution Approach 1:

The patent applies self-service by enabling the UE to autonomously determine the presence of a second transmit antenna port through RSRP measurements and SINR calculations, without requiring explicit notification from the network node. The UE independently performs the detection by comparing RSRP values and calculating SINR, thereby eliminating the need for additional signaling while maintaining detection capability.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent uses RSRP measurements and SINR calculations as intermediary metrics to indirectly determine the presence of the second transmit antenna port. Instead of directly detecting the antenna port mapping, the UE measures reference signal received power and signal-to-interference-plus-noise ratio, which serve as intermediaries that reveal the presence information without requiring explicit signaling from the network.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2787662B1Antenna port detection
Publication Date: 2018.02.28 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP2787662B1 patent drawingFigure 1~2
  • EP2787662B1 patent drawingFigure 3~4
  • EP2787662B1 patent drawingFigure 5

AI summary

There is provided presence detection of a second transmit antenna port in a distributed antenna port system. Cell-specific reference signals, CRS, are received on a first receive antenna port and a second receive antenna port. The CRS have been transmitted by a first transmit antenna port and a second transmit antenna port in the distributed antenna port system. Reference signal received power, RSRP, measurements and reference signal resource element received power, RSRERP, measurements are estimated from the CRS. Presence is detected by comparing each one of at least one metric based on filtered RSRP measurements and filtered RSRERP measurements to a respective threshold.