PDCCH DCI Format Identification Using Polar Code and Distributed CRC
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems, particularly in LTE, the increasing number of blind detections on the User Equipment (UE) side due to varying Downlink Control Information (DCI) formats complicates decoding performance, as the traditional method of receiving the Physical Downlink Control Channel (PDCCH) leads to higher computational burdens.
Innovation Solution
A method is introduced where a distributed Cyclic Redundancy Check (CRC) bit is interleaved into the channel code based on a polar code, and padding bits are used as frozen bits to determine the format identifier field, optimizing the placement of padding bits within the DCI format to improve decoding performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional blind detection method is used for receiving PDCCH, then all possible DCI formats are detected, but the number of blind detections increases as the candidate item of the number of bits corresponding to the DCI increases
Solution Approach 1:
The patent applies preliminary action by placing the format identifier field at the beginning of the DCI format, allowing the UE to determine the DCI format and number of padding bits before performing polar code coding. This preliminary determination enables the UE to reduce the number of blind detections by knowing the exact format to decode, rather than attempting all possible formats. The first sub-information block is positioned to be decoded first, providing format information that guides subsequent decoding operations.
Solution Approach 2:
The patent segments the DCI format into multiple sub-information blocks, with the first sub-information block containing the format identifier field. This segmentation allows the UE to process and identify the format type separately from the remaining data, enabling more efficient blind detection by narrowing down the search space based on the identified format rather than testing all possible formats equally.
2Adaptability or versatility
If the length of DCI format varies, then different information can be transmitted, but the UE must perform blind detection on all possible formats increasing computational burden
Solution Approach 1:
The patent reduces computational burden through preliminary action by enabling the UE to determine the DCI format length and structure before performing full decoding operations. The format identifier field in the first sub-information block provides this preliminary information, allowing the UE to adapt its decoding process to the specific format rather than performing exhaustive blind detection across all possible formats, thereby reducing energy consumption.
Solution Approach 2:
The patent employs parameter changes by using the format identifier field to dynamically indicate the DCI format type and number of padding bits. This allows the system to adaptively change the decoding parameters based on the identified format, enabling versatile DCI transmission while reducing the computational burden by focusing processing resources on the specific format rather than all possible formats.
3Reliability
If padding bits are added to match bit block length, then polar code coding can be performed, but the position of padding bits affects decoding performance
Solution Approach 1:
The patent applies local quality by strategically placing padding bits in specific positions within the DCI format rather than uniformly distributing them. The number of padding bits Q is determined based on the specific DCI format and information block structure, optimizing decoding performance for each local context. This localized optimization of padding bit placement improves overall decoding reliability without requiring complex global restructuring of the code.
Solution Approach 2:
The patent uses parameter changes to adapt the number and position of padding bits based on the specific DCI format and information block requirements. The parameter Q (number of padding bits) is dynamically adjusted according to the format identifier and content length, allowing the system to optimize decoding performance for different message types while maintaining a relatively simple code construction framework based on polar codes.
Data Source
AI summary
The present disclosure discloses a method and device in user equipment and a base station for wireless communication. The base station equipment sequentially generates a first information block, performs first channel coding and transmits a first radio signal, wherein the first information block includes bits in a first sub-information block, the first information block is used to generate L check bits, the first information block and the L check bits are sequentially mapped into the first bit block after being interleaved, the first bit block is used as an input of the first channel coding, the value of the first sub-information-block is related to the Q, the positions of the bits in the first sub-information-block in the first bit block are prior to the check bit whose position is front-most among the L check bits in the first bit block.