PUCCH Repetition Indication via DCI CRC Scrambling
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Solution Overview
Problem
Current wireless communication systems, particularly in 5G networks, face limitations in configuring the number of Physical Uplink Control Channel (PUCCH) repetitions during the random access procedure, which affects cell range, coverage, and reliability, especially for ultra-reliable and low-latency communications (URLLC) applications.
Innovation Solution
The proposed solution involves scrambling a portion of the cyclic redundancy check (CRC) bits in the downlink control information (DCI) to indicate the number of PUCCH transmissions, allowing user equipment (UE) to determine and perform the appropriate number of transmissions based on the received sequence of bits, thereby enhancing the reliability and coverage of PUCCH feedback during the random access procedure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the number of PUCCH repetitions is increased to improve cell range and coverage, then reliability is improved, but device complexity and configuration complexity increase
Solution Approach 1:
The patent changes the parameter representation method by using CRC bit scrambling instead of explicit higher-layer signaling. The number of PUCCH repetitions is indicated through different CRC scrambling sequences (e.g., different RNTI values or scrambling identities) rather than through complex configuration parameters, simplifying the device complexity while maintaining reliability improvement.
Solution Approach 2:
The patent extracts the repetition count information from the CRC field of DCI messages. By utilizing the existing CRC structure and scrambling mechanism, the repetition count is conveyed as an implicit parameter rather than requiring separate explicit signaling, thereby reducing configuration complexity while enabling reliable PUCCH repetition control.
2Length of stationary object
If explicit configuration of PUCCH repetitions is implemented, then cell range and coverage are improved, but loss of information increases due to additional signaling overhead
Solution Approach 1:
The patent merges the repetition count information with the existing CRC field in DCI messages. By combining multiple functions (error detection via CRC and repetition count indication) into a single field through scrambling mechanisms, the signaling overhead is minimized while still providing explicit configuration for PUCCH repetitions to extend cell range.
Solution Approach 2:
The CRC scrambling mechanism serves multiple functions simultaneously: it provides error detection capability and conveys the repetition count information. This multi-functionality reduces the need for separate dedicated signaling fields, thereby reducing signaling overhead while maintaining the ability to configure PUCCH repetitions for extended cell range.
3Productivity
If CRC bits are scrambled to indicate PUCCH transmissions, then productivity of random access procedure is improved, but measurement precision of CRC verification decreases
Solution Approach 1:
The patent segments the CRC bit sequence and applies different scrambling operations to different portions or uses different scrambling identities for different DCI types. This segmentation allows the system to maintain CRC verification precision for error detection while simultaneously embedding repetition count information, thereby improving random access procedure efficiency without sacrificing measurement precision.
Data Source
AI summary
According to example embodiment, a method may include receiving, by a user device from a network node, a message including a first set of bits of a cyclic redundancy check that is scrambled based on a sequence of bits, wherein the sequence of bits indicates or is associated with a number of physical uplink control channel (PUCCH) transmissions within a random access procedure; descrambling, by the user device, the cyclic redundancy check to obtain the sequence of bits; determining, by the user device based on the sequence of bits, the number of physical uplink control channel transmissions within the random access procedure; and performing, by the user device within the random access procedure, a transmission of a physical uplink control channel the determined number of times.