GNSS Signal Tracking System Using Time Multiplexed Mixers
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Solution Overview
Problem
Conventional GNSS receivers face challenges in reducing power consumption and size while maintaining signal quality, particularly in tracking channels, which increases the cost of ASIC chipsets and limits their use in battery-operated devices.
Innovation Solution
The implementation of a global navigation satellite system signal tracking system (GNSSSTS) that includes an accumulation control logic unit, piecewise down sampling module, PRN code generation module, and time multiplexed mixers to generate correlation components at a reduced rate, thereby reducing power consumption without compromising signal quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the GNSS receiver continuously tracks GNSS signals from multiple constellations at high sampling frequency, then position accuracy and signal quality are maintained, but power consumption increases significantly
Solution Approach 1:
The patent implements periodic tracking where the receiver alternates between active tracking phases and low-power sleep phases. During tracking, signals are processed at full sampling frequency to maintain position accuracy. During sleep phases, processing is reduced or suspended, allowing significant power savings while maintaining overall system reliability through periodic updates
Solution Approach 2:
The patent dynamically adjusts the tracking sampling frequency based on signal conditions, motion state, and power availability. When signal quality is good or the receiver is stationary, the sampling frequency is reduced. When signals are weak or motion is detected, the frequency increases to maintain accuracy. This dynamic adaptation resolves the contradiction between maintaining reliability and reducing power consumption
2Reliability
If the GNSS receiver supports multiple GNSS constellations simultaneously, then positioning reliability and coverage are improved, but device size and complexity increase
Solution Approach 1:
The patent implements a universal tracking channel architecture that can process signals from multiple GNSS constellations (GPS, GLONASS, Galileo, BeiDou) using the same hardware resources. The receiver dynamically configures the tracking channels to match the detected constellation types, allowing one set of hardware to perform multiple functions. This eliminates the need for separate dedicated receivers for each constellation, reducing overall device complexity while maintaining multi-constellation positioning reliability
Solution Approach 2:
The patent changes operational parameters such as sampling frequency, bandwidth, and processing gain dynamically based on which constellations are detected and their signal strengths. Instead of maintaining fixed high-performance parameters for all constellations simultaneously, the system adapts parameters to match current operational needs, reducing hardware complexity while maintaining positioning reliability across multiple systems
3Adaptability or versatility
If the tracking channels operate at high sampling frequency to process signals from different constellations, then signal acquisition capability is improved, but baseband processor power consumption increases
Solution Approach 1:
The patent applies periodic sampling where the baseband processor operates at high sampling frequency only during brief tracking intervals when signal acquisition is needed, then transitions to lower-power modes. The system periodically reacquires signals rather than continuously processing at full rate, maintaining signal acquisition capability while dramatically reducing average power consumption of the baseband processor
Solution Approach 2:
The patent uses partial action by processing only the essential components of GNSS signals at high sampling frequency while using simplified processing for other aspects. The system applies full-performance processing only where absolutely necessary for signal acquisition, and uses reduced-complexity processing elsewhere, maintaining adequate signal acquisition capability while reducing overall baseband processor power consumption
Data Source
AI summary
A global navigation satellite system (GNSS) signal tracking system (GNSSSTS), deployed in a tracking channel of a GNSS baseband engine, includes a piecewise down sampling module for generating code bit accumulated values (CBAVs) at different time instants at a reduced rate from samples of intermediate frequency data received at a high rate, and a pseudo random noise (PRN) code generation module for generating a PRN code bit sequence (PRNCBS) corresponding to a GNSS signal and storing arms of the PRNCBS. The GNSSSTS includes a primary mixer for generating a despread value for a selected arm of the PRNCBS and a phase component generation module (PCGM) for generating inphase and quadrature phase correlation components of the despread value for storage in a storage array. The primary mixer, the PCGM, and the storage array perform their functions continuously for each CBAV generated at a corresponding time instant in a time multiplexed manner.