Binary Tree PDCCH Search Space Design for 5G NR

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Solution Overview

Problem

Current wireless communication systems, particularly in 5G new radio (NR) technology, face challenges in blind decoding and channel estimation, which affect the efficiency and reliability of PDCCH decoding in multiple-access systems.

Innovation Solution

A binary tree-based PDCCH search space design is implemented, allowing for the identification of aggregation levels, determination of decoding candidates, and channel estimation for resource element groups (REGs) to enhance blind decoding and channel estimation performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional PDCCH search space design is used, then blind decoding complexity increases, but channel estimation efficiency remains suboptimal

Engineering Contradiction:
Improveblind decoding efficiencyVSAvoidblind decoding complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The search space is segmented into multiple search space sets, each associated with different aggregation levels. This segmentation allows the UE to divide blind decoding attempts across multiple organized groups rather than searching through all candidates uniformly, reducing overall complexity while maintaining decoding efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The aggregation level profile is dynamically configured and can be adjusted based on channel conditions and traffic requirements. The network can update the aggregation level profile via RRC signaling, allowing the system to adapt blind decoding complexity to actual needs rather than using fixed static configurations.

Inventive Principle:
Principle #15Dynamics

2Reliability

If channel estimation is performed for each decoding candidate independently, then decoding reliability improves, but computational complexity increases

Engineering Contradiction:
Improvedecoding reliabilityVSAvoidchannel estimation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Channel estimation results are merged and reused across multiple decoding candidates that share the same CCEs. When multiple decoding candidates utilize identical or overlapping CCE resources, the channel estimation performed for those CCEs is reused rather than re-computed, significantly reducing computational complexity while maintaining decoding reliability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system performs channel estimation only when necessary - specifically when CCEs are first encountered or when channel conditions change. Subsequent decoding candidates that reuse the same CCEs benefit from the previously performed channel estimation, allowing the system to serve multiple decoding operations with a single channel estimation effort.

Inventive Principle:
Principle #25Self-service

Data Source

PatentUS11032756B2Binary tree based PDCCH search space design
Publication Date: 2021.06.08 QUALCOMM INC
  • US11032756B2 patent drawing
  • US11032756B2 patent drawing
  • US11032756B2 patent drawing

AI summary

A method and apparatus for enhancing channel estimation by using a binary tree based PDCCH search space in a new radio wireless communication system is disclosed. For example, a UE may identify an aggregation level profile having an aggregation level value for one or more aggregation levels, wherein each aggregation level corresponds to a respective number of resources to use for decoding a PDCCH, determine one or more decoding candidates for the UE from among a plurality of available decoding candidates defined as nodes in a binary tree for a search space based on the aggregation level profile, determine respective CCEs corresponding to each of the one or more decoding candidates, each respective CCE including one or more REGs, and performing channel estimation for each of the respective CCEs for use in demodulating and decoding downlink control information for the UE in the PDCCH.