Adaptive Random Access Preamble Length for Wireless Networks

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Solution Overview

Problem

Current random access procedures in cellular networks, such as LTE, are inefficient and energy-intensive due to the use of fixed-length random access channel (RACH) preambles, which do not adapt to varying user equipment requirements, leading to increased re-transmissions and interference.

Innovation Solution

Implementing random access sequences of different lengths in wireless communications networks, allowing base stations to dynamically adjust preamble lengths based on user equipment requirements, reducing energy consumption and improving detection accuracy by avoiding re-transmissions and minimizing interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If fixed-length random access preambles are used in cellular networks, then the random access procedure is standardized and simple to implement, but energy consumption increases and detection accuracy decreases due to inability to adapt to varying user equipment requirements

Engineering Contradiction:

Improveadaptability of preamble lengthVSAvoidenergy consumption of user equipment

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamic preamble length adaptation where the base station configures different preamble lengths (first preamble length and second preamble length) based on user equipment requirements such as cell radius, channel conditions, and service type. This allows the system to transition from static fixed-length preambles to dynamic adaptive lengths, optimizing energy consumption by using shorter preambles when possible while maintaining detection accuracy when needed.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of preamble length from a fixed value to a variable parameter that can be adjusted based on network conditions. The base station configures multiple preamble formats with different lengths (e.g., 839 symbols, 139 symbols) and assigns them appropriately, allowing the system to optimize the balance between detection accuracy and energy consumption by selecting appropriate preamble lengths for different scenarios.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If fixed-length random access preambles are used, then implementation is simplified, but re-transmissions increase leading to higher error rates and interference

Engineering Contradiction:

Improvedetection accuracy of random accessVSAvoidcomplexity of random access procedure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces dynamic preamble length selection where the base station configures different preamble lengths based on detected user equipment requirements. This allows the system to adapt preamble length to specific scenarios (e.g., larger cell radius requires longer preambles for better detection), thereby improving reliability without requiring complete redesign of the random access procedure.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent modifies the preamble length parameter to be configurable and adaptive rather than fixed. By introducing multiple preamble formats with different lengths (such as 839 symbols for normal conditions and 139 symbols for specific scenarios), the system can optimize detection accuracy for different cell sizes and channel conditions while maintaining manageable implementation complexity through standardized configuration procedures.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If longer preamble sequences are used to improve detection accuracy, then detection performance increases, but transmission time and energy consumption increase

Engineering Contradiction:

Improvedetection accuracy of preambleVSAvoidtransmission time of random access

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent implements configurable preamble length parameters that can be adjusted based on detection requirements. By providing multiple preamble formats with different lengths (e.g., 839 symbols, 139 symbols) and allowing the base station to configure appropriate lengths based on cell radius and channel conditions, the system optimizes the trade-off between detection accuracy and transmission time, using longer preambles only when necessary.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces dynamic adaptation of preamble length where the system selects appropriate preamble lengths based on real-time network conditions and user equipment requirements. This dynamic selection allows the system to use shorter preambles for fast access scenarios and longer preambles for scenarios requiring higher detection accuracy, thereby optimizing the time-performance trade-off.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentEP3560269B1Base stations, user equipment and wireless communications system for adaptive preamble length

Publication Date: 2023.09.06 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV

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AI summary

A base station is configured to control a wireless communications network cell of a wireless communications network. The base station is configured to establish a connection to a first user equipment and to a second user equipment using a random access process. For establishing the connection to the first user equipment, the base station is configured to use a sequence of a first random access preamble, the sequence having a first length. For establishing the connection of the second user equipment, the base station is configured to use a sequence of a second random access preamble, the sequence having a second length.