Dual Receiver Wireless Device Power Saving

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Solution Overview

Problem

Wireless terminals and smart sensors face high power consumption due to the need to constantly monitor paging or beacon channels, even in idle modes, especially in OFDM systems which require continuous operation of wide band and high resolution ADC and FFT engines, leading to increased power drain.

Innovation Solution

Implementing a dual-receiver system with a narrow band receiver to determine whether to wake up the wide band receiver, allowing for efficient power management by processing a separate narrow band signal to decide on waking up the wide band receiver, and using a transmitter to generate a wide band signal with a narrow band signal containing wake-up information, reducing unnecessary power usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the wide band receiver continuously monitors the paging channel in OFDM system, then the terminal can detect messages in real time, but the power consumption increases significantly

Engineering Contradiction:

Improvemessage detection capabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The receiver is segmented into two functional parts: a narrow band receiver that continuously monitors the paging channel with low power consumption, and a wide band receiver that processes full OFDM signals only when wake-up indicators are detected. This segmentation allows the system to maintain message detection capability while significantly reducing average power consumption during idle periods.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The wide band receiver operates periodically rather than continuously. It is activated only at specific intervals when the narrow band receiver detects wake-up indicators, transforming continuous high-power operation into periodic low-power operation while maintaining the ability to detect messages when they are transmitted.

Inventive Principle:

Principle #19Periodic action

2Reliability

If the ADC and FFT engines operate continuously to enable signal detection, then the terminal can detect signals at any time, but the power consumption increases

Engineering Contradiction:

Improvesignal detection capabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The signal processing function is segmented between the narrow band receiver (continuous operation) and the wide band receiver (periodic operation). The narrow band receiver handles continuous paging channel monitoring with simplified processing, while the computationally intensive ADC and FFT operations in the wide band receiver are performed only periodically when needed, reducing overall power consumption.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of performing full OFDM processing (excessive action) continuously, the system performs partial processing continuously via the narrow band receiver and full processing only when necessary. This partial action approach maintains adequate signal detection capability while avoiding the excessive power consumption of continuous full-bandwidth processing.

Inventive Principle:

Principle #16Partial or excessive action

3Reliability

If the terminal wakes up periodically to check for messages, then it can receive communications, but unnecessary wake-ups consume power

Engineering Contradiction:

Improvemessage reception capabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The narrow band receiver performs preliminary monitoring of the paging channel continuously and identifies wake-up indicators before activating the wide band receiver. This preliminary action allows the system to determine in advance whether a full wake-up is necessary, preventing unnecessary power consumption from activating the wide band receiver when no messages are present.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The narrow band receiver acts as an intermediary between the paging channel and the wide band receiver. It filters and pre-processes the paging channel information, extracting wake-up indicators that trigger wide band receiver activation. This intermediary function reduces the frequency of wide band receiver wake-ups to only when actual messages are indicated, conserving power while maintaining reception capability.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS7672258B1Signalling channel and radio system for power saving in wireless devices

Publication Date: 2010.03.02 MICROSOFT TECHNOLOGY LICENSING LLC

AI summary

Wireless devices, transmitters, systems and methods are provided that have a narrow band signalling channel and a wide band channel, for example an OFDM channel. In order to save power, the wireless device is nominally powered down with the exception of a receiver specific to the narrow band signalling channel. Once instructed to do so over the narrow band signalling channel, the wireless device wakes up the rest of its wide band receive circuitry.