Concurrent PRACH Transmissions for Random Access Reliability
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Solution Overview
Problem
Current wireless communication systems face challenges in improving the reliability and efficiency of random access procedures, particularly in contention-free concurrent physical random access channel (PRACH) transmissions, due to poor channel conditions and misalignment of beams between user equipment (UE) and base stations, which leads to resource consumption and potential failures.
Innovation Solution
A method and apparatus for wireless communication that enables user equipment (UE) to transmit multiple concurrent PRACH transmissions, allowing for simultaneous or overlapping transmissions of different random access preambles, based on configurations received from the base station, which include indications, preamble indices, and transmission power, to enhance reliability and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the UE performs one RA procedure at a time, then the device complexity and control mechanism remain simple, but the reliability and efficiency of RA procedures deteriorate under poor channel conditions
Solution Approach 1:
The patent combines multiple RA procedures into a single concurrent transmission opportunity. The UE transmits multiple PRACH transmissions simultaneously using different beams, merging what would traditionally be sequential operations into a parallel operation, thereby improving reliability without proportionally increasing complexity
Solution Approach 2:
The patent introduces dynamic beam selection and concurrent transmission control. The UE dynamically determines which beams to use and whether to perform concurrent transmissions based on channel conditions, resolving the contradiction by making the system adaptable rather than fixed
2Reliability
If the UE retransmits RA preamble message with higher transmission power, then the reliability of RA procedure improves, but the power consumption increases
Solution Approach 1:
The patent segments the transmission effort into multiple concurrent PRACH transmissions using different beams rather than sequential retransmissions with increasing power. This allows the UE to distribute the transmission task across parallel operations, achieving reliability improvement without the power consumption penalty of repeated high-power transmissions
Solution Approach 2:
The patent changes the transmission parameter from power level to spatial beam direction. Instead of increasing power for retransmission, the system uses different beam directions for concurrent transmissions, achieving the same reliability goal through a different parameter dimension that is less costly in terms of power consumption
3Productivity
If the UE transmits multiple concurrent PRACH transmissions, then the reliability and efficiency of RA procedure improve, but the device complexity and control mechanisms increase
Solution Approach 1:
The patent applies preliminary beam selection and configuration before the actual transmission. The UE pre-determines which beams to use for concurrent transmissions based on downlink beam measurements, performing the complex selection logic in advance rather than during the transmission decision moment, thereby managing complexity
Solution Approach 2:
The patent relies on downlink feedback information (beam measurements, signal quality) to guide the concurrent transmission decision. By using feedback from the downlink to determine uplink transmission strategy, the system reduces the complexity of real-time decision-making through information-driven control
Data Source
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AI summary
In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may transmit a first physical random access channel (PRACH) transmission that includes a first random access (RA) preamble to a base station. The apparatus may determine whether to transmit to the base station a second PRACH transmission that is concurrent with the first PRACH transmission in time, wherein the second PRACH includes a second RA preamble. The apparatus may transmit, to the base station, the second PRACH transmission that includes the second RA preamble when the second PRACH transmission is determined to be transmitted. The first RA preamble and the second RA preamble may be different, and the first RA preamble and the second RA preamble may be concurrently transmitted in a same PRACH occasion or in different PRACH occasions that overlap in time.