SPS Receiver Mode Switching for Linearity Under Transmitter Interference
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Solution Overview
Problem
Satellite positioning system (SPS) receivers face performance degradation due to high transmitter output power, requiring high bias current to maintain linearity while consuming excessive power when the transmitter output power is low.
Innovation Solution
Implementing a dynamic mode selection mechanism for the SPS receiver, switching between high linearity and low power modes based on transmitter output power levels, with adjustable bias current settings for circuit blocks like LNA, mixer, and LO generator, using a switch point and hysteresis to optimize power consumption and performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high bias current is used to maintain linearity in the SPS receiver, then linearity performance is improved, but power consumption increases
Solution Approach 1:
The patent implements dynamic mode selection that switches between high linearity mode and low power mode based on real-time transmitter output power levels. The receiver dynamically adjusts its operating state rather than maintaining a fixed bias current, allowing optimization of both linearity and power consumption under different operating conditions.
Solution Approach 2:
The patent changes the bias current parameter dynamically based on transmitter output power levels. When transmitter power is high, higher bias current is applied to maintain linearity; when transmitter power is low, lower bias current reduces power consumption. This parameter adaptation resolves the contradiction between maintaining consistent performance and reducing energy usage.
2Use of energy by moving object
If low bias current is used to reduce power consumption in the SPS receiver, then power consumption is reduced, but linearity performance deteriorates
Solution Approach 1:
The patent dynamically adjusts the bias current parameter based on transmitter output power conditions. Instead of using low bias current unconditionally, the system increases bias current when transmitter power exceeds a threshold, thereby maintaining linearity only when necessary and achieving overall power savings without permanent performance degradation.
Solution Approach 2:
The receiver transitions between different operational states (high linearity mode and low power mode) based on real-time conditions. This dynamic adaptation allows the system to optimize power consumption during normal operation while maintaining performance when interference conditions arise.
3Reliability
If high linearity mode is always used to ensure performance, then linearity is maintained, but power consumption increases
Solution Approach 1:
The patent implements a dynamic mode selection mechanism that switches between high linearity mode and low power mode based on transmitter output power levels. Instead of continuously operating in high linearity mode, the system activates this mode only when transmitter power exceeds a predetermined threshold, thereby maintaining performance when needed while reducing power consumption during normal operation.
Solution Approach 2:
The system periodically monitors transmitter output power levels and adjusts its operating mode accordingly. This periodic assessment allows the receiver to alternate between power-saving and high-performance states, achieving overall optimization rather than continuous high-power operation.
4Use of energy by moving object
If dynamic mode switching is implemented to optimize power consumption, then power consumption is reduced, but device complexity increases
Solution Approach 1:
The patent employs a feedback mechanism where the receiver monitors transmitter output power levels and uses this information to control mode selection. The output power detection circuit provides feedback to the mode selection logic, creating a closed-loop system that automatically adjusts operating mode based on actual conditions without requiring complex external control.
Solution Approach 2:
The receiver performs self-adjustment by monitoring its own operating conditions and automatically selecting the appropriate mode. The system uses its internal resources (power detection capabilities, mode selection logic) to manage its own power consumption without requiring external intervention or complex control systems.
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 maintains high linearity and reduces power consumption by dynamically adjusting bias currents according to transmitter output power levels, ensuring good receiver performance with extended battery life in portable devices.
Implementation Method 1
Hysteresis may be used for the transitions between the first and second modes
Data Source
AI summary
A satellite positioning system (SPS) receiver that can provide good performance with low power consumption is described. The SPS receiver may be operated in one of multiple modes, which may be associated with different bias current settings for the SPS receiver. One of the modes may be selected based on output power level of a transmitter co-located with the SPS receiver. The bias current of an LNA, a mixer, and/or an LO generator within the SPS receiver may be set based on the selected mode. In one design, a first (e.g., lower power) mode may be selected for the SPS receiver if the transmitter output power level is below a switch point. A second (e.g., high linearity) mode may be selected if the transmitter output power level is above the switch point. The second mode is associated with more bias current for the SPS receiver than the first mode.