MIMO Grant Differentiation via DCI Bit Flag
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems face challenges in differentiating between downlink (DL) and uplink (UL) grants in Multiple Input Multiple Output (MIMO) transmissions without increasing the complexity of user equipment, particularly in supporting UL and DL MIMO, and existing systems lack a method to efficiently share formats between DL and UL grants to reduce blind decodings.
Innovation Solution
A method is introduced to generate control information for grants by determining a DCI format, attaching a cyclic redundancy check (CRC), and channel-coding the control information, which includes a bit flag to differentiate between UL and DL grants, or by masking the CRC with specific bit patterns to maximize Hamming distance between UL and DL grant bit patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate DCI formats are used for UL and DL grants in MIMO systems, then grant differentiation is achieved, but user equipment complexity increases due to more blind decodings
Solution Approach 1:
The patent merges the DCI formats for UL and DL grants by using a common DCI format structure. Instead of maintaining separate formats, the invention combines them into a unified format that can represent both UL and DL grant types, thereby reducing the number of blind decodings required by user equipment while preserving reliable grant differentiation through the use of a grant type indicator field.
Solution Approach 2:
The patent creates a universal DCI format that serves multiple functions - it can indicate both UL grants and DL grants within the same format structure. This multi-functional approach allows a single DCI format to replace what would traditionally require separate formats, reducing user equipment complexity while maintaining the ability to differentiate between grant types through embedded indicator fields.
2Device complexity
If DCI formats are shared between UL and DL grants, then user equipment complexity is reduced, but grant differentiation becomes more difficult
Solution Approach 1:
The patent introduces a grant type indicator field as an intermediary element within the shared DCI format. This indicator acts as a mediator that enables clear differentiation between UL and DL grants even though the overall format is shared. The indicator field provides the necessary distinction without requiring separate formats, thus resolving the contradiction between format sharing and grant differentiation.
Solution Approach 2:
The patent uses parameter changes within the DCI format structure to enable grant differentiation. By incorporating a grant type indicator parameter and potentially using different parameter combinations or values within the shared format, the system can clearly distinguish between UL and DL grants while maintaining a unified format structure that reduces user equipment complexity.
3Adaptability or versatility
If MIMO is supported in both UL and DL, then system versatility improves, but the number of blind decodings increases
Solution Approach 1:
The patent merges the DCI format structures for UL MIMO and DL MIMO grants into a single unified format. This consolidation allows the system to support MIMO in both directions while reducing the total number of distinct formats that user equipment must decode, thereby maintaining versatility while lowering the blind decoding burden.
Solution Approach 2:
The patent creates a universal DCI format capable of indicating both UL and DL MIMO grants through the use of grant type indicators and appropriate parameter configurations. This multi-functional format enables full MIMO support in both uplink and downlink while avoiding the need for separate specialized formats for each MIMO direction, thus reducing blind decoding requirements.
Data Source
AI summary
The present invention relates to a method for transmitting an uplink or downlink grant in a wireless communication system that supports uplink and downlink multiple input multiple output (MIMO) schemes. The method comprises: determining a downlink control information (DCI) format for an uplink or downlink grant to generate control information: attaching a cyclic redundancy check (CRC) for detecting an error in the created control information; and channel-coding the CRC-attached control information, wherein the control information comprises a bit flag for distinguishing whether the grant is an uplink grant or a downlink grant.