PRACH Timing Advance Configuration for Satellite Round Trip Delay

Solution Overview

Problem

In wireless communication systems, particularly in satellite communication, the long round trip delay between terminal devices and network devices leads to increased cyclic prefix length and resource overhead during random access, which is inefficient.

Innovation Solution

Configuring a time advance for the physical random access channel (PRACH) sending time relative to downlink frame timing of terminal devices, allowing them to send PRACH information in advance, thereby reducing cyclic prefix length and resource overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If terminal devices send PRACH information after downlink frame timing in satellite communication, then the communication follows standard timing protocol, but the cyclic prefix length increases and resource overhead increases due to long round trip delay

Engineering Contradiction:

Improvetiming protocol complianceVSAvoidcyclic prefix length

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies preliminary action by configuring terminal devices to send PRACH information before the downlink frame timing arrives. The network device provides timing advance configuration information that enables terminal devices to advance their PRACH transmission time, compensating for the long round trip delay in satellite communication. This preliminary transmission allows the network device to receive PRACH information in the expected time window without requiring extended cyclic prefix.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If terminal devices send PRACH information after downlink frame timing in satellite communication, then the communication follows standard timing protocol, but the resource overhead increases due to long round trip delay

Engineering Contradiction:

Improvetiming protocol complianceVSAvoidresource overhead

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies preliminary action by configuring terminal devices to send PRACH information before the downlink frame timing arrives. The network device provides timing advance configuration information that enables terminal devices to advance their PRACH transmission time, compensating for the long round trip delay in satellite communication. This preliminary transmission allows the network device to receive PRACH information in the expected time window without requiring extended cyclic prefix.

Inventive Principle:

Principle #10Preliminary action

3Quantity of substance

If terminal devices send PRACH information in advance relative to downlink frame timing, then the cyclic prefix length decreases and resource overhead reduces, but the timing protocol must be adjusted

Engineering Contradiction:

Improvecyclic prefix lengthVSAvoidtiming configuration

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by modifying the timing parameters of PRACH transmission. The network device configures timing advance parameters that shift the PRACH transmission time earlier than the standard downlink frame timing. This parameter adjustment allows terminal devices to transmit PRACH information in advance, reducing the required cyclic prefix length and resource overhead while maintaining protocol compliance through configured parameters.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20240179754A1Method and apparatus for configuring physical random access channel (PRACH)

Publication Date: 2024.05.30 BEIJING XIAOMI MOBILE SOFTWARE CO LTD

AI summary

A method for configuring a physical random access channel (PRACH), performed by a network device, where the method includes: sending PRACH configuration information to a terminal device in a specified region, wherein the PRACH configuration information comprises a PRACH format and a time advance for a PRACH sending time relative to downlink frame timing of the terminal device.