Multicast Channel Subframe Decoding with Adaptive Reference Signal Patterns

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Solution Overview

Problem

In wireless communication systems with multiple multicast broadcast single frequency networks (MBSFNs), time-division multiplexing leads to excessive memory usage and increased latency due to differing channel characteristics, making it difficult to perform channel estimation across MBSFNs using a single reference signal pattern.

Innovation Solution

Implementing different frequency domain reference signal patterns for different multicast channel subframes, allowing for self-decodable and non-self-decodable subframes based on indicated patterns, reducing latency and buffering delays.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single reference signal pattern is used across multiple MBSFNs with different channel characteristics, then device complexity is reduced, but measurement precision deteriorates due to inability to perform accurate channel estimation

Engineering Contradiction:
Improvereference signal pattern configurationVSAvoidchannel estimation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent applies local quality by configuring different reference signal patterns for different MBSFNs based on their specific channel characteristics. Each MBSFN area can have optimized reference signal density and placement tailored to its local propagation conditions, thereby achieving accurate channel estimation without requiring a single complex universal pattern across all areas.

Inventive Principle:
Principle #3Local quality

2Reliability

If reference signals are buffered for time-division multiplexed MBSFNs, then reliability of channel estimation is improved, but loss of time increases due to excessive latency

Engineering Contradiction:
Improvechannel estimation reliabilityVSAvoiddecoding latency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent implements preliminary action by ensuring that each PMCH subframe contains all necessary reference signals within itself, allowing UEs to perform channel estimation immediately upon receiving the subframe without waiting for buffered reference signals from other subframes. This self-contained approach eliminates buffering delays while maintaining estimation reliability.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If reference signal density is increased across all PMCH subframes, then measurement precision is improved, but use of energy increases due to higher overhead

Engineering Contradiction:
Improvechannel estimation accuracyVSAvoidUE energy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent applies local quality by allowing different reference signal densities in different MBSFNs based on their specific channel conditions. MBSFNs experiencing severe fading or mobility can use higher reference signal density, while stable channels can use lower density, thereby optimizing estimation accuracy while minimizing overall energy consumption and overhead.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4038807B1Decoding physical multicast channel subframes according to different reference signal patterns
Publication Date: 2025.07.16 QUALCOMM INC
  • EP4038807B1 patent drawingFigure 1
  • EP4038807B1 patent drawingFigure 2
  • EP4038807B1 patent drawingFigure 3

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive a multicast channel configuration that indicates a set of multicast channel time domain resources allocated to a multicast channel for a first multicast broadcast area. The UE may receive an indication of a first set of time domain resources, of the set of multicast channel time domain resources, that have a first reference signal pattern that differs in frequency domain density as compared to a second reference signal pattern used for at least one of a second set of time domain resources of the set of multicast channel time domain resources or a second multicast broadcast area. The UE may decode the first set of time domain resources based at least in part on the first reference signal pattern. Numerous other aspects are provided.