RACH Configuration Using Variable Cyclic Prefix and Guard Time
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Solution Overview
Problem
Current random access channel (RACH) configurations in wireless communication networks, particularly in 5G New Radio (NR) systems, face inefficiencies due to fixed cyclic prefix (CP) and guard time (GT) settings based on maximum round-trip time (RTT), which can lead to longer signal durations and increased power consumption, especially in Integrated-Access-Backhaul (IAB) networks with varying RTTs between nodes.
Innovation Solution
Adopting a RACH configuration that sets CP and GT lengths to the difference between estimated maximum and minimum RTTs, utilizing an estimated timing advance value to optimize transmission timing and waveform configuration, thereby reducing signal duration and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If CP and GT are set to the maximum RTT to ensure all UEs can decode RACH signals, then decoding reliability is improved, but signal duration and power consumption increase
Solution Approach 1:
The patent applies dynamics by making the CP and GT lengths adjustable rather than fixed. The system can dynamically select different CP/GT configurations based on the specific RTT conditions of each UE, allowing the signal duration to adapt to actual network conditions rather than always using the maximum possible value.
Solution Approach 2:
The patent changes the parameters of CP and GT lengths from fixed maximum values to variable values that can be selected based on estimated RTT. By introducing multiple configuration options and allowing parameter adjustment, the system optimizes the balance between decoding reliability and signal duration for different UE locations.
2Reliability
If CP and GT are set to the maximum RTT to accommodate all UEs, then decoding reliability is improved, but power consumption increases
Solution Approach 1:
The system dynamically adjusts CP and GT lengths based on actual UE RTT conditions rather than using a fixed maximum configuration. This dynamic adaptation allows the system to reduce power consumption for UEs with shorter RTTs while maintaining sufficient decoding reliability for all UEs.
Solution Approach 2:
The patent introduces parameter changes by allowing CP and GT lengths to vary based on estimated RTT values. The system can select from multiple configuration sets, choosing parameters that optimize power consumption for each specific UE's communication conditions.
3Device complexity
If a fixed RACH configuration is used for all UEs, then system simplicity is maintained, but adaptability to different RTT conditions deteriorates
Solution Approach 1:
The patent segments the RACH configuration into multiple distinct sets, each optimized for different RTT conditions. Instead of using a single fixed configuration, the system divides the configuration space into multiple segments that can be selectively applied based on UE characteristics, improving adaptability while managing complexity through structured organization.
Solution Approach 2:
The system transitions from a static fixed configuration to a dynamic configurable system that can adapt to different RTT conditions. By implementing dynamic selection mechanisms, the system maintains manageable complexity while significantly improving adaptability to varying network conditions.
Data Source
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AI summary
Aspects of the present disclosure provide for random access channel (RACH) configuration in wireless communication systems. In some examples, a RACH configuration may be selected for use by a scheduled entity in transmitting a RACH signal to a scheduling entity based on an estimated timing advance value. The RACH configuration may include, for example, a transmission time of the RACH signal and/or a RACH waveform configuration identifying at least a cyclic prefix (CP) length and a guard time (GT) for the RACH signal. In some examples, the CP and GT length may each be set to the difference between an estimated maximum round-trip time (RTT) and an estimated minimum RTT between the scheduled entity and the scheduling entity. In some examples, the timing advance value may be estimated as the estimated minimum RTT.