PDCCH Decoding Complexity Reduction via DMRS Metric Thresholding

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Solution Overview

Problem

Current wireless communication systems face challenges in efficiently decoding physical downlink control channels (PDCCH) due to high complexity and resource consumption, particularly in scenarios like 5G NR systems operating in unlicensed spectrum bands, where channel access restrictions and power spectral density requirements complicate sidelink communications.

Innovation Solution

Implementing mechanisms for sidelink user equipment (UE) to multiplex S-SSB transmissions with CSI-RS in a frequency band, using configurations such as frequency-interlaced or subchannel-based multiplexing to meet OCB requirements, and configuring different resource pools for S-SSB and non-S-SSB slots to optimize channel utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If PDCCH decoding is performed using traditional methods in 5G NR systems, then control channel functionality is maintained, but decoding complexity and resource consumption increase significantly

Engineering Contradiction:

ImprovePDCCH decoding complexityVSAvoiddecoding efficiency

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

The patent extracts and removes invalid or redundant PDCCH candidate resources from the decoding process by comparing DMRS metrics against thresholds. This eliminates unnecessary decoding operations while preserving valid PDCCH candidates, directly reducing decoding complexity without sacrificing detection accuracy

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of performing exhaustive decoding on all PDCCH candidate resources, the patent applies partial action by selectively decoding only those candidates that meet predefined DMRS metric thresholds. This approach avoids excessive decoding operations on obviously invalid candidates while ensuring all potentially valid candidates are processed

Inventive Principle:

Principle #16Partial or excessive action

2Reliability

If multiple PDCCH candidate resources are monitored to ensure reliable control channel reception, then communication reliability is improved, but power consumption and processing resources increase

Engineering Contradiction:

ImprovePDCCH reception reliabilityVSAvoidUE power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent performs preliminary evaluation of PDCCH candidate resources by calculating and comparing DMRS metrics (such as RSRP or SINR) against predefined thresholds before committing to full decoding operations. This preliminary filtering action identifies and eliminates invalid candidates early, preventing unnecessary power consumption from decoding operations on doomed candidates while maintaining reliability by preserving all valid candidates for decoding

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS20250106857A1Reduced complexity physical downlink control channel decoding

Publication Date: 2025.03.27 QUALCOMM INC

AI summary

Wireless communications systems and methods related to communicating control information are provided. A method of wireless communication performed by a user equipment (UE) may include monitoring a first set of physical downlink control channel (PDCCH) candidate resources for a PDCCH communication from a network unit, receiving, from the network unit, a plurality of demodulation reference signals (DMRSs), and decoding, based on a metric associated with the plurality of demodulation reference signals (DMRSs) satisfying a threshold, the PDCCH communication.