R-PDCCH Candidate Positioning for Relay Node Search Space
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems face inefficiencies in transmitting downlink allocation information and uplink grant information for relay nodes, particularly in determining the search space for R-PDCCH detection in backhaul downlink subframes.
Innovation Solution
A method for relay nodes to receive downlink control information through R-PDCCH by determining candidate positions in a downlink subframe, monitoring for R-PDCCH transmission, and receiving control information, with candidate positions set as Virtual Resource Blocks and higher aggregation levels combining adjacent positions, allowing efficient transmission and detection of downlink and uplink information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If downlink control information is transmitted through traditional PDCCH in backhaul downlink subframe, then relay nodes can receive control information, but the transmission efficiency and resource utilization are insufficient
Solution Approach 1:
The patent introduces R-PDCCH as an intermediary channel specifically designed for relay node control information transmission. This new channel acts as a mediator between the base station and relay nodes, separating the control information transmission for relay nodes from the traditional PDCCH used for user equipment, thereby improving transmission efficiency and resource utilization.
Solution Approach 2:
The patent segments the control information transmission by creating a dedicated R-PDCCH channel for relay nodes, distinct from the traditional PDCCH for user equipment. This segmentation allows for optimized resource allocation and transmission parameters specific to relay node requirements, improving overall system efficiency.
2Measurement precision
If search space for R-PDCCH detection is determined using complex methods, then detection accuracy improves, but the complexity of determining search space increases
Solution Approach 1:
The patent applies preliminary action by pre-determining the search space for R-PDCCH detection based on aggregation level and candidate position information. The search space is established in advance through systematic rules rather than complex real-time calculations, achieving both detection accuracy and reduced complexity.
Solution Approach 2:
The patent uses parameter changes by varying the aggregation level (L=1,2,4,8) to determine different search space configurations. By changing this key parameter, the system can adapt the search space size and complexity to match detection requirements without introducing overly complex determination methods.
3Reliability
If candidate R-PDCCH positions are densely distributed, then detection reliability improves, but the number of monitoring positions and complexity increase
Solution Approach 1:
The patent applies partial action by selecting specific candidate positions for R-PDCCH monitoring rather than monitoring all possible positions. The relay node monitors a subset of candidate positions determined by aggregation level, achieving sufficient detection reliability without the excessive complexity of monitoring every possible position.
Solution Approach 2:
The patent introduces dynamics by making the number and distribution of candidate positions adaptive to the aggregation level. As aggregation level changes, the candidate position configuration dynamically adjusts, allowing the system to balance detection reliability with monitoring complexity based on current channel conditions and requirements.
Data Source
AI summary
A method is provided for a base station to transmit downlink control information to a relay through a Relay-Physical Downlink Control Channel (R-PDCCH). The base station transmits one or more candidate positions for the R-PDCCH. The base station further determines, based on the one or more candidate positions, a Virtual Resource Block (VRB) set for the R-PDCCH. Moreover, the base station transmits the downlink control information to the relay through the R-PDCCH. The one or more candidate positions are within the VRB set including at least one VRB, and a candidate position for the R-PDCCH of a higher aggregation level includes a combination of 2 adjacent candidate positions among candidate positions for the R-PDCCH of a lower aggregation level.