Multi-mode Base Station Power Management

Solution Overview

Problem

In wireless communications systems, base stations in low population density areas or with varying load requirements waste power by transmitting full synchronization signals continuously, causing interference to neighboring cells and reducing data throughput.

Innovation Solution

Implementing a base station with multiple modes of operation, including a sleep mode that reduces transmission power and signaling rate based on activity levels, allowing seamless transitions between modes in response to schedule information or detected user activity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If base station transmits full synchronization signals continuously, then timing synchronization and channel estimation accuracy are maintained, but power is wasted and interference is generated in low activity periods

Engineering Contradiction:

Improvetiming synchronization accuracyVSAvoidbase station transmission power

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The base station dynamically adjusts its operation mode between active and sleep states based on detected user activity. When no users are detected, the base station enters sleep mode with reduced transmission power. When users are detected, it transitions to active mode with full transmission power, optimizing both energy efficiency and synchronization accuracy.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the transmission power parameter of synchronization signals based on operational mode. In active mode, full power is used to maintain precise timing synchronization. In sleep mode, reduced power is used to conserve energy while still providing sufficient signaling for user detection and basic synchronization.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If base station transmits full synchronization signals continuously, then active users maintain precise timing synchronization, but interference is generated in neighboring cells

Engineering Contradiction:

Improvetiming synchronizationVSAvoidinterference to neighboring cells

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The base station dynamically adjusts its operation mode between active and sleep states based on detected user activity. When no users are detected, the base station enters sleep mode with reduced transmission power. When users are detected, it transitions to active mode with full transmission power, optimizing both energy efficiency and synchronization accuracy.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the transmission power parameter of synchronization signals based on operational mode. In active mode, full power is used to maintain precise timing synchronization. In sleep mode, reduced power is used to conserve energy and reduce interference to neighboring cells.

Inventive Principle:

Principle #35Parameter changes

3Loss of energy

If base station reduces synchronization signal power, then power is conserved and interference is reduced, but wireless terminals may have difficulty detecting base station presence

Engineering Contradiction:

Improvebase station transmission powerVSAvoidbase station detection by wireless terminals

Core Design Contradiction:

Loss of energyVSDifficulty of detecting and measuring

Solution Approach 1:

The base station transmits synchronization signals periodically at reduced power during sleep mode. This periodic transmission at lower power levels allows wireless terminals to detect the base station's presence and maintain basic synchronization while consuming less energy compared to continuous full-power transmission.

Inventive Principle:

Principle #19Periodic action

Data Source

PatentEP1949564B1Methods and apparatus for use in a wireless communications system that uses a multi-mode base station

Publication Date: 2010.01.20 QUALCOMM INC

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AI summary

A multi-mode base station includes a transmit standby mode and an active mode. Transmit standby mode of base station operation is a low power/low interference level of operation as compared to active mode. In transmit standby mode at least some of the synchronization signaling such as pilot tone signaling is reduced in power level and/or rate with respect to the active mode. In transmit standby mode, the base station has no active state registered wireless terminals being serviced but may have some sleep state registered wireless terminals being serviced. Mode transitions from active to transmit standby may be in response to: a detected period of inactivity, scheduling information, base station mode change signals, and/or detected wireless terminal state transition. Mode transitions from transmit standby to active may be in response to: scheduling information, access signals, wake-up signals, hand-off signals, wireless terminal state change signals, and/or base station mode change signals.