Single RF Chain for GPS and Glonass Signal Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing GPS, Galileo, and Glonass satellite navigation systems require dual RF chains to support multiple frequency bands, leading to increased area and power consumption, which is costly and less attractive to customers.
Innovation Solution
A single receive RF chain with a single local oscillator that overlaps non-overlapping frequency bands into a shared intermediate frequency passband, using a mixer circuit with in-phase and quadrature outputs, and digital processing to separate GPS and Glonass signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If dual RF chains are used to support GPS, Galileo, and Glonass frequency bands, then multi-band reception capability is improved, but device area and power consumption increase
Solution Approach 1:
The patent merges multiple RF chains into a single shared RF chain that sequentially processes GPS, Galileo, and Glonass signals. The single RF chain is time-multiplexed to handle different frequency bands, eliminating the need for separate dual RF chains while maintaining multi-band reception capability. This reduces device area by consolidating hardware components.
Solution Approach 2:
The system dynamically reconfigures the single RF chain to operate at different frequency bands and bandwidths depending on which satellite system is being processed. The RF chain parameters (center frequency, bandwidth, gain) are dynamically adjusted between GPS L1, Galileo E1, and Glonass L1 bands, enabling versatile multi-band reception with a single static hardware configuration.
2Adaptability or versatility
If dual RF chains are used to support GPS, Galileo, and Glonass frequency bands, then multi-band reception capability is improved, but power consumption increases
Solution Approach 1:
The patent combines multiple power-consuming RF chains into a single shared RF chain that is time-multiplexed across different satellite systems. By having only one active RF chain at any given time instead of multiple simultaneous chains, power consumption is significantly reduced while still supporting GPS, Galileo, and Glonass reception capabilities.
Solution Approach 2:
The system employs periodic time-multiplexed operation where the single RF chain alternates between processing different satellite systems in sequence. The RF chain is activated for GPS processing, then deactivated and reconfigured for Galileo, then for Glonass, creating a periodic operation pattern that reduces average power consumption compared to having all chains simultaneously active.
3Adaptability or versatility
If separate local oscillators are provided for GPS/Galileo and Glonass, then frequency band coverage is improved, but device complexity and cost increase
Solution Approach 1:
The patent makes a single local oscillator universal by programming it to generate different center frequencies for different satellite systems. The same LO circuitry produces 1575.42 MHz for GPS L1, 1575.42 MHz for Galileo E1, and 1602.0 MHz for Glonass L1 by changing control parameters, eliminating the need for separate dedicated oscillators for each frequency band.
Solution Approach 2:
The system changes the operational parameters of the single local oscillator to cover different frequency bands. By modifying the LO center frequency parameter and bandwidth parameter based on which satellite system is being processed, the same hardware component achieves multi-band coverage without increasing device complexity.
4Adaptability or versatility
If additional RF chains are added to support Glonass in GPS products, then Glonass reception capability is improved, but manufacturing cost increases
Solution Approach 1:
The patent merges Glonass reception capability into the existing single RF chain used for GPS processing. By time-multiplexing the same RF chain and adding Glonass-specific digital processing for frequency de-multiplexing, the system achieves triple-system support (GPS, Galileo, Glonass) without adding separate RF hardware, thereby reducing manufacturing costs.
Solution Approach 2:
The system uses digital copying and processing rather than additional analog RF hardware to support Glonass. The single RF chain's output is digitally processed with Glonass-specific correlation and frequency de-multiplexing algorithms, creating a virtual Glonass reception path that avoids the cost of physical duplicate RF components.
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 approach reduces area and power consumption by approximately 50% and 75%, respectively, while maintaining accurate time, position, and velocity estimation, making the technology more economically viable.
Implementation Method 1
a mixer circuit including an in-phase and quadrature (I,Q) pair of mixers fed by the RF circuit and having a local oscillator with in-phase and quadrature outputs coupled to the mixers respectively, the mixer circuit operable to inject and substantially overlap the at least two non-overlapped frequency bands with each other into the IQ IF sections
Data Source
AI summary
An electronic circuit separates frequency-overlapped GLONASS and GPS overlapped in an approximately 4 MHz passband. The circuit uses a multiple-path analog-to-digital converter circuit (ADC). A sampling rate circuit is coupled to concurrently operate the analog-to-digital converter circuit at a sampling rate between about 60 Msps and about 80 Msps. A digital processing circuit includes storage defining complex de-rotation and low pass filtering. The digital processing circuit is fed by the analog-to-digital converter circuit and is operable A) to establish an access rate and respective distinct phase increments for the complex de-rotation, B) to execute the complex de-rotation by combinations of trigonometric multiplications using the distinct phase increments approximately concurrently and C) to execute the low pass filtering on the complex de-rotation resulting at the access rate and respective distinct phase increments, thus delivering GPS and Glonass signals separated from each other.