Shared LO Diversity Receiver for Low-Power Secondary Downconversion

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Solution Overview

Problem

Conventional diversity receivers experience high power consumption when operating in diversity mode due to the transmission of a primary oscillator signal over a long path to a secondary receiver, which increases energy usage and can lead to noise issues.

Innovation Solution

A diversity receiver design that shares a primary local oscillator (LO) signal between the primary and secondary receivers, utilizing a supplemental downconverter to down-convert the secondary receive signal with the primary LO signal, thereby reducing power consumption and minimizing the signal path.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the primary oscillator signal is transmitted over a long path to the secondary receiver, then the secondary receiver can down-convert the secondary signal, but power consumption increases substantially

Engineering Contradiction:
Improvesignal reception capabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent merges the primary and secondary local oscillator circuits into a single shared oscillator that generates both LO signals locally at the secondary receiver. This eliminates the need for long-distance signal transmission and the substantial power consumption associated with it, while maintaining the capability to down-convert both primary and secondary signals.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces a shared local oscillator as an intermediary component that generates both LO signals locally at the secondary receiver. This intermediary eliminates the need for direct long-distance transmission of the primary oscillator signal, thereby reducing power consumption while maintaining signal reception capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the primary oscillator signal is transmitted over a long path to the secondary receiver, then the secondary receiver can utilize the LO signal, but noise performance deteriorates

Engineering Contradiction:
Improvesignal processing capabilityVSAvoidnoise
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent merges the local oscillator functionality into a single shared circuit at the secondary receiver, eliminating long transmission paths that introduce noise. The combined oscillator generates both LO signals locally, ensuring clean signal generation without the noise degradation associated with long-distance transmission.

Inventive Principle:
Principle #5Merging (Combining)

3Use of energy by moving object

If the secondary receiver's modules are powered down to reduce power consumption, then energy efficiency improves, but the ability to process secondary signals independently is lost

Engineering Contradiction:
Improvepower consumptionVSAvoidsignal processing flexibility
Core Design Contradiction:
Use of energy by moving objectVSAdaptability or versatility

Solution Approach 1:

The patent implements a universal shared local oscillator that performs multiple functions: generating LO signals for both primary and secondary receivers, and enabling both diversity mode and different frequency monitoring mode operations. This multi-functional design maintains signal processing flexibility while reducing power consumption, as the same oscillator circuit serves multiple purposes without requiring separate powered-down modules.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration results in significant power savings, improved noise performance, and reduced power consumption by enabling the secondary receiver's modules to be powered down, while maintaining efficient signal processing in diversity mode.

Implementation Method 1

a frequency synthesizer to generate a local oscillator signal

Methodology Applied
Scientific EffectFrequency synthesis:

Implementation Method 2

a mixer to down-convert the received signal using the local oscillator signal generated by the frequency synthesizer

Methodology Applied
Scientific EffectMixing:

Data Source

PatentEP3297173B1Diversity receiver with shared local oscillator signal in diversity mode
Publication Date: 2019.07.31 QUALCOMM INC
  • EP3297173B1 patent drawingFigure 1
  • EP3297173B1 patent drawingFigure 2
  • EP3297173B1 patent drawingFigure 3~4

AI summary

A multi-mode receiver is disclosed that is reconfigurable to share a local oscillator signal in diversity mode to save power consumption. In an exemplary embodiment, an apparatus includes a primary receiver having a primary mixer configured to down-convert a primary signal and a secondary mixer configured to down-convert a secondary signal in carrier aggregation mode. The apparatus also includes a supplemental mixer that uses a shared primary local oscillator (LO) signal generated by a shared primary frequency synthesizer in diversity mode to reduce power consumption. The apparatus further includes a controller configured to disable the secondary mixer and to enable the supplemental mixer to down-convert the secondary signal when operating in the diversity mode.