Short DCI Format Reduces PDCCH Resource Overhead
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Solution Overview
Problem
The LTE Rel-10 communication system faces a significant challenge in efficiently managing PDCCH transmission resources, particularly when a large number of UEs require PDCCH transmission within a cell, leading to resource shortages due to the high resource requirements for cross carrier scheduling and Carrier Aggregation (CA).
Innovation Solution
The implementation of a short DCI format that includes indices for Resource Block (RB) sets, transmitted through higher layer signaling, which reduces the number of CCEs needed for PDCCH transmission by configuring the RB allocation and modulation schemes through higher layer signaling, allowing for efficient resource allocation and reduced blind decoding attempts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If cross carrier scheduling is applied with Carrier Aggregation, then the base station can transmit PDCCH through another serving cell, but the specific serving cell needs large amounts of resources for PDCCH transmission
Solution Approach 1:
The patent extracts the RB allocation information from the DCI format and transmits it separately through higher layer signaling (RRC signaling). This separation removes the bulk of resource allocation information from the control channel, significantly reducing the number of bits required in DCI formats while maintaining the ability to schedule resources across multiple component carriers.
Solution Approach 2:
The patent performs preliminary configuration of RB allocation information through higher layer signaling before actual data transmission. By pre-configuring the resource block sets and their associations with component carriers, the system eliminates the need to transmit this information repeatedly in each DCI, thereby reducing PDCCH resource requirements.
2Manufacturing precision
If DCI formats include complete RB allocation information, then resource allocation can be precisely controlled, but the number of bits required for DCI formats increases
Solution Approach 1:
The patent extracts RB allocation information from the DCI format and transmits it separately through higher layer signaling (RRC signaling). This separation removes the bulk of resource allocation information from the control channel, significantly reducing the number of bits required in DCI formats while maintaining the ability to schedule resources across multiple component carriers.
Solution Approach 2:
The patent segments the resource allocation information into two parts: (1) RB set configuration and component carrier association transmitted through higher layer signaling, and (2) simplified DCI formats that reference the pre-configured RB sets. This segmentation allows precise resource allocation while minimizing control channel overhead.
3Productivity
If a large number of UEs require PDCCH transmission within a cell, then system capacity increases, but PDCCH transmission resources become insufficient
Solution Approach 1:
The patent extracts RB allocation information from the DCI format and transmits it separately through higher layer signaling (RRC signaling). This separation removes the bulk of resource allocation information from the control channel, significantly reducing the number of bits required in DCI formats while maintaining the ability to schedule resources across multiple component carriers.
Solution Approach 2:
The patent changes the parameter representation by using compact DCI formats that reference pre-configured RB sets rather than explicitly specifying resource allocations. This parameter transformation reduces the bit length of DCI formats from potentially 60+ bits to much shorter formats, enabling support for more UEs within the available PDCCH resources.
Data Source
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AI summary
Methods and apparatus are provided for transmitting and receiving a control signal. Indices of Resource Block (RB) sets are transmitted through higher layer signaling. Downlink Control Information (DCI) generated in a short DCI format is transmitted from a Base Station (BS) to a terminal. The DCI includes a first index indicating an RB set having at least one allocated RB and a second index indicating the at least one allocated RB. The terminal determines whether short DCI format is configured to be used. When the short DCI format is configured to be used, the first index and second index are received. The terminal communicates through the at least one allocated RB identified by the first and second indices.