PDCCH Mapping to Multiple Search Spaces in LTE
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Solution Overview
Problem
The limitation of the PDCCH being transmitted only in association with the cell-specific reference signal restricts the common search space to a single subframe, leading to inefficient control information notification and significant deterioration in transmission efficiency in LTE communication systems.
Innovation Solution
The proposed solution involves enhancing the communication system by allowing the PDCCH to be mapped to both cell-specific and UE-specific search spaces, enabling more flexible and efficient transmission of control information across multiple subframes through carrier aggregation using TDD and FDD systems, thereby improving transmission efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the PDCCH is transmitted only in association with the cell-specific reference signal, then the control information can be reliably transmitted using a fixed mapping rule, but the common search space is restricted to a single subframe, leading to inefficient control information notification and deterioration in transmission efficiency
Solution Approach 1:
The patent applies universality by enabling the PDCCH to be mapped to multiple types of search spaces (both common search space and UE-specific search space) rather than restricting it to only common search space. This allows the control channel to serve multiple functions and be transmitted in multiple subframes, improving transmission efficiency while maintaining reliability through the association with UE-specific reference signals.
Solution Approach 2:
The patent introduces dynamics by allowing flexible configuration of search spaces and their association with different reference signals. The system can dynamically allocate PDCCH to appropriate search spaces based on terminal requirements and network conditions, rather than using a fixed static mapping, thereby improving adaptability and transmission efficiency.
2Productivity
If the PDCCH is mapped to multiple search spaces including UE-specific search space, then control information notification becomes more flexible and efficient across multiple subframes, but the system complexity increases due to multiple reference signal associations
Solution Approach 1:
The patent applies segmentation by dividing the search space into distinct types (common search space and UE-specific search space), each with specific mapping rules and reference signal associations. This segmentation allows the system to manage complexity by handling different search spaces separately while achieving overall improved transmission efficiency through their combined use.
Data Source
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AI summary
A terminal includes a transmission unit that transmits a physical uplink control channel by using a physical uplink control channel resource for transmitting HARQ-ACK, in a subframe n. The physical uplink control channel resource is given by a value of a first control channel element used for transmitting the corresponding physical downlink control channel or the corresponding extended physical downlink control channel, in at least a subframe n-k. The element k is included only in a first set defined by a first table, in a case where the terminal is not configured with a higher layer parameter. The element k is given based on the first set defined by the first table and a second set defined by a second table, in a case where the terminal is configured with the higher layer parameter.