Prefix Error-Detection Code for 5G Control Channel Length Indication
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Solution Overview
Problem
The existing methods for indicating the length of a control information block in a physical downlink control channel in 5G mobile networks are prone to errors due to unprotected headers, leading to a high false alarm rate in downlink control channels, even with cyclic redundancy check protection.
Innovation Solution
The use of unused bits in the downlink control information (DCI) is replaced with prefix error-detection code (PEDC) words, which have a minimal Hamming distance of 2, allowing for efficient and accurate determination of the control information block length without increasing redundancy, and are generated independently of the control information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If direct header indication is used to indicate control information block length, then the indication method is simple, but the false alarm rate increases due to unprotected headers
Solution Approach 1:
The patent applies preliminary action by pre-defining a mapping relationship between unused bits and control information block lengths before transmission. The base station pre-configures this mapping and notifies the user equipment, allowing the UE to directly determine the length without complex real-time decoding, thus simplifying the indication method while maintaining reliability through the predefined structure.
Solution Approach 2:
The patent introduces an intermediary mechanism by using a specific mapping relationship table that connects unused bits to control information block lengths. This mapping acts as an intermediary that translates the unprotected header information into reliable length indication, reducing the false alarm rate while keeping the indication method simple.
2Adaptability or versatility
If more different DCI formats are used to accommodate complex 5G PDCCH structure, then the adaptability improves, but the number of blind decoding attempts increases beyond the 44 limit
Solution Approach 1:
The patent applies universality by designing a unified DCI format structure that can accommodate multiple 5G PDCCH scenarios. Instead of creating separate DCI formats for different cases, a single format with flexible field configurations is used, allowing the same format to serve multiple functions and maintain adaptability while staying within the 44 blind decoding attempt limit.
Solution Approach 2:
The patent uses parameter changes by dynamically adjusting the lengths and positions of fields within the DCI format based on the specific transmission scenario. The control information block length, resource allocation fields, and other parameters are variable, allowing the same DCI format structure to adapt to different 5G PDCCH requirements without increasing the number of distinct formats.
Data Source
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AI summary
The invention relates to a communication transmitter (201) for transmitting a control message over a physical downlink control channel towards a communication entity in a mobile communication network (200). The communication transmitter (201) comprises: a processor (203) which is configured to process a control block to obtain the control message, the control fame having a first portion (101) and a second portion (102), the first portion comprising downlink control information bits indicating information relating to data transmission over the mobile communication network (200), wherein the processor (203) is configured to insert prefix error detection code bits into the second portion of the control block to obtain the control message; and a communication interface (205) being configured to transmit the control message over the mobile communication network (200). The invention also relates to a communication receiver (231 ) for receiving the control message sent from the a communication transmitter (201 ) over the communication network (200), wherein the communication receiver (231) comprises a communication interface (233) configured to receive the control message over the communication network; and a processor (235) configured to decode the prefix error detection code bits of the second portion to reliably define the length of the first portion (101) of the control block.