Relay Station Random Access Timing Control

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Solution Overview

Problem

In radio communication systems with relay stations, self-interference occurs when the base station and relay station transmit and receive signals simultaneously, leading to incorrect reception of messages during the random access procedure.

Innovation Solution

The relay station limits its reception from the base station during signal transmission to the mobile station, and the base station controls the timing of its responses based on whether the relay station or mobile station is the transmission source, ensuring that messages are sent at optimal times to avoid interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the relay station performs random access to the base station using the same procedure as mobile stations, then the random access procedure is simplified, but self-interference occurs when the base station sends response messages during the relay station's transmission period

Engineering Contradiction:

Improverandom access procedure compatibilityVSAvoidmessage reception accuracy

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The base station determines in advance whether the transmission source is a relay station or mobile station, and prepares appropriate response timing before actually sending the response message. This preliminary determination allows the base station to avoid sending messages during the relay station's transmission period, preventing self-interference while maintaining procedure simplicity

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The base station dynamically adjusts its response timing based on the type of transmission source. For relay stations, messages are sent outside the transmission period to avoid interference, while for mobile stations, normal timing is used. This dynamic adaptation resolves the contradiction between procedure simplicity and message reception accuracy

Inventive Principle:

Principle #15Dynamics

2Productivity

If the base station sends response messages within a flexible timing window, then scheduling efficiency is improved, but the relay station cannot correctly receive messages when sent during its transmission period

Engineering Contradiction:

Improvescheduling efficiencyVSAvoidmessage reception accuracy

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The base station applies different message sending strategies to different transmission sources within the same system. For relay stations, messages are sent during periods when the relay station is not transmitting, while for mobile stations, the flexible timing window is fully utilized. This localized differentiation maintains scheduling efficiency while ensuring reliable reception for relay stations

Inventive Principle:

Principle #3Local quality

Data Source

PatentEP3468297B1Radio communication system, base station, relay station, and radio communication method

Publication Date: 2020.06.17 FUJITSU CONNECTED TECH LTD

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AI summary

Random access through a relay station is smoothly performed. The relay station (20) performs wireless communications with a base station (10), and a mobile station (30) performs wireless communications with the base station (10) or relay station (20). The relay station (20) limits reception of a radio signal from the base station (10) at timing at which a radio signal is transmitted to the mobile station (30). The relay station (20) transmits a message #1 about random access to the base station (10). The base station (10) transmits a message #2 at timing which is determined based on whether a transmission source of the message #1 is the relay station (20). The relay station (20) receives the message #2 from the base station (10) .