Random Access Preamble Power Boosting for Beam Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the multi-beam scenario of new radio (NR) systems, user equipment (UE) faces challenges in determining the appropriate uplink beam for random access, leading to unsuccessful preamble transmissions due to insufficient power boosting when switching beams.
Innovation Solution
A method that involves judging whether the currently selected beam is identical to recorded beams, clearing previous beams, and boosting the pilot transmit power when the pilot power boost counter does not reach its maximum value, ensuring the preamble is transmitted at a higher power when switching beams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the UE transmits preamble at the same power for all beams during random access, then the device complexity is reduced, but the reliability of preamble reception deteriorates when switching beams
Solution Approach 1:
The patent applies dynamics by making the transmit power adjustable based on beam switching events. Instead of using a fixed power level for all preamble transmissions, the system dynamically increases the transmit power when the UE switches from one beam to another beam during random access retransmissions. This dynamic power adjustment ensures reliable preamble reception while maintaining manageable complexity through clear triggering conditions.
2Device complexity
If the UE boosts transmit power only when the beam is not changed during two consecutive retransmissions, then the power control complexity is reduced, but the reliability of preamble transmission deteriorates when switching beams
Solution Approach 1:
The patent applies feedback by using the beam switching event itself as the triggering mechanism for power boosting. When the UE detects that it has switched from one beam to another beam during preamble retransmission, this feedback information about the beam change directly triggers the power boosting action. This feedback-based approach ensures reliable transmission without complex power control logic.
3Ease of operation
If the UE maintains the same transmit power when switching from beam 3 to beam 1, then the ease of operation is improved, but the reliability of preamble reception deteriorates
Solution Approach 1:
The patent applies preliminary action by preparing the power boosting mechanism in advance through clear protocol definition. The protocol pre-establishes that power boosting should occur when beam switching is detected during retransmission attempts. This preliminary setup ensures that when beam switching occurs (e.g., from beam 3 to beam 1), the power boosting is automatically triggered without requiring complex real-time decisions, thus maintaining ease of operation while improving reliability.
Data Source
AI summary
A random access method includes: initiating, by user equipment (UE), a random access based on at least one of: initial access, uplink synchronization loss, or reconstruction; selecting, by the UE, a beam to transmit a preamble; determining, by the UE, whether a currently selected beam for transmitting the preamble is identical to multiple recorded beams previously selected for transmitting the preamble; determining, by the UE, that the currently selected beam is identical to one of the multiple recorded beams; determining, by the UE, a value of a pilot power boost counter not to reach a maximum value; and transmitting, by the UE, the preamble at a boosted pilot transmit power.