Blind Search Management for 5G NR Channel Estimation Limits

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Solution Overview

Problem

In 5G New Radio (NR) systems, user equipment (UE) faces a high channel estimation burden due to limited channel estimation capability, especially when configured with multiple parallel control resource sets and high aggregation levels, leading to increased decoding latency and complexity in monitoring the physical downlink control channel (PDCCH).

Innovation Solution

The solution involves dynamically managing blind decodings and control channel elements (CCEs) by determining the number of CCEs to reduce, splitting them across different aggregation levels, and selectively dropping blind decoding candidates based on predefined rules or implicit signaling to maintain channel estimation within UE capabilities, without requiring additional RRC signaling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the UE is configured with multiple parallel control resource sets and high aggregation levels, then the network can provide robust control channel coverage and support multiple services, but the channel estimation burden and decoding complexity increase significantly

Engineering Contradiction:
Improvecontrol channel coverageVSAvoidchannel estimation burden
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the control channel monitoring task by dividing the search space into multiple control resource sets (CORESETs) with different aggregation levels. The UE can selectively monitor different CORESETs based on service requirements, rather than monitoring all possible candidates uniformly. This segmentation reduces the overall channel estimation burden while maintaining reliable coverage for critical services through high aggregation level CORESETs.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the UE monitors all blind decoding candidates across multiple search spaces, then no control information is missed, but the decoding latency and processing complexity increase

Engineering Contradiction:
Improvecontrol information detectionVSAvoiddecoding latency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent introduces dynamic blind decoding management where the UE adaptively adjusts its monitoring behavior based on current network conditions and service priorities. The network can dynamically indicate which search spaces or CORESETs should be monitored in specific time instances, allowing the UE to reduce monitoring activity when full monitoring is not required, thereby reducing decoding latency while maintaining reliable detection when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of blind decoding quantity from a static configuration to a dynamically adjustable parameter. Through DCI indicators or MAC CE signaling, the network can modify the number of blind decodes the UE performs in different time instances, enabling the system to optimize between detection reliability and decoding latency based on instantaneous traffic conditions.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the network configures a large number of PDCCH candidates across multiple aggregation levels, then control channel robustness is improved, but the UE's processing capability requirements exceed practical limits

Engineering Contradiction:
Improvecontrol channel robustnessVSAvoidUE processing capability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies partial action by having the UE monitor only a subset of all possible PDCCH candidates at any given time. Instead of requiring the UE to process all configured candidates uniformly, the system allows partial monitoring of search spaces based on priority and current needs, reducing UE processing requirements while maintaining control channel robustness through selective monitoring of high-priority candidates.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3738255B1Apparatuses and methods for managing blind searches
Publication Date: 2023.09.27 NOKIA TECHNOLOGIES OY
  • EP3738255B1 patent drawingFigure 1
  • EP3738255B1 patent drawingFigure 2
  • EP3738255B1 patent drawingFigure 3

AI summary

Systems, methods, apparatuses, and computer program products for managing or monitoring of the control channel in new radio (NR) through blind searches are provided. One method may include determining whether a channel estimation limit has been reached for a user equipment. When it is determined that the channel estimation limit has been reached, the method may include selecting blind decoding candidate(s) to be dropped from different control resource set(s) or search space set(s), and removing the selected blind decoding candidate(s) from a set of monitored candidates.