Random Access Preamble Power Control for Wireless Devices
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Solution Overview
Problem
In wireless communication systems, particularly in Evolved Universal Terrestrial Radio Access Networks (E-UTRAN), the Random Access preamble transmission process is inefficient due to the need for power ramping, which leads to increased power consumption and prolonged procedure completion times, especially for low-cost Machine-Type Communication (MTC) devices that require frequent connections.
Innovation Solution
The method involves using the power from the last successfully completed Random Access procedure as the initial power for subsequent preamble transmissions, and adjusting the power ramping step based on the priority of the access procedure, allowing for quicker and more efficient completion of Random Access procedures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If power ramping is used for Random Access preamble transmission, then the probability of successful transmission is improved, but power consumption increases and procedure completion time is prolonged
Solution Approach 1:
The patent applies preliminary action by storing the last successfully used preamble power value before a Random Access procedure begins. This stored power value is then reused as the initial power for the first preamble transmission, eliminating the need to start from a configured initial power and perform power ramping steps. The preparation of storing the power value occurs in advance, allowing the device to skip unnecessary power increment steps and reduce both power consumption and access latency.
2Reliability
If power ramping steps are performed for each Random Access procedure, then transmission reliability is improved, but the time to complete the procedure increases
Solution Approach 1:
The patent applies preliminary action by pre-storing the last successfully used preamble power value before the Random Access procedure starts. This stored value is directly applied to the first preamble transmission, eliminating the need to execute multiple power ramping steps. By preparing the optimal power value in advance based on historical successful transmissions, the patent reduces access latency while maintaining transmission reliability.
3Adaptability or versatility
If initial power configuration is used for preamble transmission, then the procedure follows standard protocol, but power consumption and access latency increase for frequent connections
Solution Approach 1:
The patent applies dynamics by making the initial power for preamble transmission adaptive rather than static. Instead of always using a configured initial power value, the system dynamically selects the initial power based on whether a previous successful transmission power is available. This dynamic adjustment allows the system to comply with standard protocols when necessary while optimizing for faster access and lower power consumption during frequent connections, thereby improving overall access efficiency.
Data Source
AI summary
Methods and apparatuses are disclosed for improving Random Access preamble transmission in a wireless communication system. The method includes receiving a configuration of an initial power and a power ramping step for a preamble transmission. The method also includes transmitting a first Preamble using a first power based on at least the initial power and the power ramping step, wherein the first Preamble is the last preamble transmission of a first Random Access procedure. The method includes determining whether the first Random Access procedure is successfully completed. The method also includes transmitting a second Preamble using a second power based on at least the first power, wherein the second Preamble is the first preamble transmission of a second Random Access procedure.