ePDCCH Blind Decode Reduction via DMRS Quality Assessment
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Solution Overview
Problem
The enhanced physical downlink control channel (ePDCCH) in LTE requires a large number of blind decodes, leading to excessive decoding hardware costs and power consumption, and decoding cannot commence until the entire sub-frame is received, which poses challenges in meeting tight latency requirements.
Innovation Solution
A receiving circuitry that evaluates control channel message candidates by calculating and comparing DMRS sequences and quality measures, allowing for early termination of the blind decode process and reducing the number of candidates tested, thereby saving processor time and battery power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large number of blind decodes are performed to ensure reliable ePDCCH detection, then the reliability of control channel reception is improved, but the decoding hardware cost and power consumption increase excessively
Solution Approach 1:
The patent performs preliminary actions by calculating DMRS sequences and computing quality measures for all DMRS candidates before conducting blind decodes. This preliminary quality assessment allows the system to identify and prioritize promising candidates, thereby reducing the number of full blind decode operations needed while maintaining detection reliability.
Solution Approach 2:
The patent introduces a quality measure parameter (based on correlation between extracted signal sequences and calculated DMRS sequences) to characterize DMRS candidates. By changing from uniform blind decode testing to quality-based selective testing, the system reduces hardware complexity while preserving reliability through intelligent candidate selection.
2Reliability
If a large number of blind decodes are performed to ensure reliable ePDCCH detection, then the reliability of control channel reception is improved, but the power consumption increases excessively
Solution Approach 1:
The patent performs preliminary quality assessment of DMRS candidates using correlation-based quality measures before committing to full blind decode operations. This preliminary filtering reduces the number of energy-intensive blind decode operations required, thereby lowering overall power consumption while maintaining detection reliability.
Solution Approach 2:
Instead of performing complete blind decodes on all possible candidates, the patent applies partial action by conducting quality assessments on all candidates but performing full decoding only on those exceeding quality thresholds. This selective approach significantly reduces power consumption while preserving reliable detection.
3Reliability
If the entire sub-frame is received before decoding ePDCCH, then accurate detection is possible, but the latency increases and tight latency requirements cannot be met
Solution Approach 1:
The patent performs preliminary calculations of DMRS sequences and quality measures as soon as reference signals are available, without waiting for the entire sub-frame. This preliminary preparation enables faster transition to blind decode operations once data arrives, reducing overall latency while maintaining detection accuracy through pre-computed quality metrics.
Solution Approach 2:
The patent skips the traditional sequential approach of receiving the entire sub-frame before any processing. Instead, it rushes through preliminary DMRS processing and quality assessment in parallel with sub-frame reception, enabling earlier initiation of blind decode operations and reducing latency.
4Quantity of substance
If fewer OFDM symbols are allocated to ePDCCH compared to PDCCH, then more resources are available for data transmission, but the UE cannot enter power saving mode as frequently
Solution Approach 1:
The patent enables the UE to self-service its power management needs by implementing efficient blind decode reduction through DMRS quality measures. The reduced processing requirements allow the UE to complete ePDCCH detection faster and enter power-saving modes more frequently, even with fewer OFDM symbols allocated to ePDCCH.
Data Source
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AI summary
The present invention relates to a receiver circuitry and an evaluation method in a receiver circuitry for controlling a decoding of a plurality of control channel message candidates by selecting control channel message candidates based on a quality measure control channel message candidates for decoding of a received control channel message(S150). The quality measure is computed for a DMRS candidate based on an extracted signal sequence and a calculated DMRS sequence (S140).