Enhanced Search Space for DCI Transmission in NCT
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Solution Overview
Problem
Existing radio communication technologies face challenges in transmitting Downlink Control Information (DCI) using a common search space, particularly in New Carrier Type (NCT) independent operation and large-bandwidth systems, where interference among common search spaces in heterogeneous networks is a concern.
Innovation Solution
The method involves determining positions of a DCI-bearing enhanced search space in both the time and frequency domains by a base station and User Equipment (UE), allowing for DCI transmission through an enhanced search space even when traditional PDCCH search spaces are not viable.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a common search space is used for DCI transmission in heterogeneous networks, then control information can be transmitted to multiple UEs, but interference among common search spaces increases
Solution Approach 1:
The patent divides the common search space into multiple UE-specific search spaces, where each UE monitors its own dedicated search space. This segmentation eliminates interference between common search spaces while maintaining the ability to transmit control information to multiple UEs simultaneously, as each UE has its own non-overlapping search space resources.
Solution Approach 2:
The patent introduces a search space indication field in the physical downlink shared channel (PDSCH) that acts as an intermediary to guide UEs to their specific search spaces. This intermediary mechanism allows the system to maintain common search space functionality while directing UEs to interference-free, UE-specific search spaces for actual DCI transmission.
2Adaptability or versatility
If an enhanced search space is introduced for DCI transmission, then DCI can be transmitted in NCT independent operation and large-bandwidth systems, but the system complexity increases
Solution Approach 1:
The patent designs the enhanced search space mechanism to serve multiple functions: it enables DCI transmission in NCT independent operation, supports large-bandwidth systems, and provides UE-specific search space allocation. By making the search space structure multi-functional, the patent achieves high adaptability without proportionally increasing complexity, as the same framework addresses multiple technical requirements.
Solution Approach 2:
The patent modifies existing search space parameters (such as search space index, monitoring occasions, and resource allocation) to create UE-specific search spaces while maintaining compatibility with existing LTE structures. By changing parameters rather than introducing entirely new structures, the patent achieves enhanced functionality with minimal increase in system complexity.
Data Source
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AI summary
Disclosed is a method for transmitting downlink control information. The method comprises: a base station determining a time domain position and a frequency domain position of an enhanced search space bearing downlink control information, and sending the downlink control information on the time domain position and the frequency domain position. The present invention further discloses an apparatus for transmitting downlink control information. By means of the solutions in the present invention, the problem that a search space of a PDCCH area cannot be used to transmit downlink control information is solved by transmitting the downlink control information through an enhanced search space when an NCT is independently operated and a low-cost terminal is accessing a large bandwidth system.