Uplink Reference Signal Transmission for Idle Period Synchronization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current wireless telecommunications systems face inefficiencies in uplink scheduling during idle periods, particularly in UMTS/LTE systems, due to the need for frequent re-synchronization and resource reallocation, which increases power consumption and reduces system performance for interactive applications like gaming and VoIP.

Innovation Solution

The method involves transmitting uplink reference signals at a reduced rate during idle periods on selective coherent bandwidths, alternating in time to cover the entire spectrum, allowing for maintained uplink synchronization and efficient radio resource management, while reducing unnecessary resource usage during long idle periods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If connectivity is shut down during long idle periods to conserve power and resources, then energy consumption is reduced, but re-connection efficiency deteriorates due to complicated re-request procedures

Engineering Contradiction:
Improvepower consumptionVSAvoidre-connection time
Core Design Contradiction:
Use of energy by moving objectVSLoss of time

Solution Approach 1:

The system performs preliminary actions by maintaining minimal uplink connectivity and transmitting reference signals during idle periods, so that when data transmission is needed, the connection can be quickly re-established without full re-connection procedures. This preliminary maintenance of connectivity resolves the contradiction by preparing the system in advance for potential data transmission.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements periodic transmission of uplink reference signals during idle periods at a reduced rate. This periodic action keeps the connection partially active, allowing for quick resumption of full data transmission while consuming less power than continuous full-rate transmission, thus resolving the contradiction between power saving and re-connection efficiency.

Inventive Principle:
Principle #19Periodic action

2Reliability

If uplink reference signals are transmitted at full rate during idle periods to maintain synchronization, then uplink synchronization quality is improved, but radio resource utilization deteriorates due to unnecessary resource usage

Engineering Contradiction:
Improveuplink synchronization qualityVSAvoidradio resource usage
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The system applies partial action by transmitting uplink reference signals at a reduced rate during idle periods rather than at full rate. This partial transmission is sufficient to maintain adequate uplink synchronization quality while significantly reducing radio resource consumption, thus resolving the contradiction between synchronization quality and resource efficiency.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The system dynamically adjusts the transmission rate of uplink reference signals based on the operational state (active vs. idle). During idle periods, the rate is reduced, while during active data transmission, the rate increases to full capacity. This dynamic adaptation resolves the contradiction by matching resource usage to actual needs.

Inventive Principle:
Principle #15Dynamics

3Speed

If connectivity is maintained during idle periods to enable immediate data transmission, then data transmission readiness is improved, but power consumption increases

Engineering Contradiction:
Improvedata transmission readinessVSAvoidpower consumption
Core Design Contradiction:
SpeedVSUse of energy by moving object

Solution Approach 1:

The system uses periodic transmission of reference signals during idle periods to maintain minimal connectivity. This periodic maintenance keeps the system ready for immediate data transmission while consuming significantly less power than continuous full-rate connectivity, thus resolving the contradiction between transmission readiness and power consumption.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system applies different quality levels of connectivity maintenance to different time periods - full-quality connectivity during active data transmission and reduced-quality (lower rate reference signal transmission) during idle periods. This local differentiation of quality resolves the contradiction by providing high readiness only when actually needed.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2016732B1Method for controlling radio communications during idle periods in a wireless system
Publication Date: 2017.06.21 NOKIA OF AMERICA CORP
  • EP2016732B1 patent drawingFigure 1
  • EP2016732B1 patent drawingFigure 2
  • EP2016732B1 patent drawingFigure 3

AI summary

A method is provided for maintaining synchronization between an AT and a base station during an idle period. During the idle period, a reduced number of uplink reference signals for uplink channel quality estimation are sent to the base station by the AT. The uplink reference signals are sent to assist coherent demodulation and uplink channel quality estimation for scheduling. During the uplink idle period, the numbers of uplink reference signals are designed to be reduced in selective coherent bandwidths. The selection of the coherent bandwidth alternates in time and covers the entire spectrum to allow the channel quality estimation through the entire spectrum.