Small Cell RACH Configuration via Macro Cell Parameters

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Solution Overview

Problem

In wireless communication systems, especially in 5G and LTE networks, there is a challenge in configuring random access channels (RACH) for small cells to avoid collisions and interference with macro cells, leading to inefficient use of resources and increased power consumption due to false RACH communications.

Innovation Solution

A method where a base station determines and transmits parameters for configuring a small cell RACH based on the configuration of a macro cell RACH, including different frequency, time domain resources, and transmission power, to reduce collisions and interference, thereby optimizing resource allocation and conserving computing and power resources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If small cell RACH uses the same configuration as macro cell RACH, then device complexity is reduced and ease of operation is improved, but collisions and interference between macro and small cell RACH communications increase

Engineering Contradiction:

ImproveRACH configuration simplicityVSAvoidRACH collision and interference

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by configuring small cell RACH with specific local parameters (different time domain resources, frequency resources, or transmission power) that are tailored to the small cell environment while maintaining compatibility with macro cell operations. This allows the small cell to have differentiated characteristics that prevent collisions without requiring complete reconfiguration of the RACH system.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes specific RACH parameters (time domain resources, frequency resources, transmission power) for small cell RACH compared to macro cell RACH. By modifying these parameters, the system avoids collisions and interference while maintaining the overall RACH functionality and reducing the need for complex device-side configuration management.

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If small cell RACH uses differentiated configuration from macro cell RACH, then collisions and interference are reduced, but device complexity and configuration management difficulty increase

Engineering Contradiction:

ImproveRACH collision and interferenceVSAvoidRACH configuration management

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent segments the RACH configuration into common parameters (shared between macro and small cells) and cell-specific parameters (differentiated for small cells). This segmentation allows devices to efficiently handle the common configuration while only needing to manage limited cell-specific parameters, reducing overall device complexity despite the differentiated small cell configuration.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The base station performs preliminary configuration by determining and signaling the small cell RACH parameters to devices before RACH operations begin. This preliminary action includes providing indications of time domain resources, frequency resources, and transmission power, so that devices can efficiently execute RACH procedures without complex real-time decision-making.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If macro cell increases transmission power to ensure RACH reception, then RACH communication reliability is improved, but power consumption increases and interference with small cell RACH worsens

Engineering Contradiction:

ImproveRACH communication reliabilityVSAvoidbase station power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies local quality by allowing macro cells and small cells to use different transmission power levels for RACH communications appropriate to their respective coverage areas and requirements. Small cells can use lower transmission power for local RACH operations, while macro cells maintain sufficient power for their larger coverage areas, optimizing overall power consumption while maintaining reliability.

Inventive Principle:

Principle #3Local quality

4Productivity

If small cell RACH communications are allowed without restriction, then small cell access efficiency is improved, but false RACH communications to macro cell increase causing resource waste

Engineering Contradiction:

Improvesmall cell access efficiencyVSAvoidcomputing and power resources

Core Design Contradiction:

ProductivityVSLoss of energy

Solution Approach 1:

The patent enables small cells to have locally optimized RACH configurations that are distinct from macro cell configurations. This allows devices to efficiently access small cells using the small cell-specific parameters while the macro cell, configured with different parameters, can distinguish and filter out RACH communications not intended for it, preventing false RACH processing and associated resource waste.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS11576203B2Random access channel configuration

Publication Date: 2023.02.07 QUALCOMM INC

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a base station may determine, based at least in part on a configuration of a first random access channel associated with a macro cell, one or more parameters of a configuration of a second random access channel associated with a small cell provided by the base station. The base station may transmit an indication of the one or more parameters of the configuration of the second random access channel. Numerous other aspects are provided.