Receiver Gain Control Using Dual RSSI Under Strong Interference
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Solution Overview
Problem
Conventional receiving devices face challenges in demodulating low-level desired waves near minimum sensitivity due to strong interfering waves, requiring increased dynamic range and power consumption, leading to circuit scale expansion and potential demodulation failure.
Innovation Solution
A receiving device with a gain control method that detects interfering waves by comparing RSSI levels before and after a channel selecting filter, reducing analog gain and increasing digital gain to maintain desired wave levels above the minimum definition level, thereby preventing saturation and reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the dynamic range of the receiving device is increased to demodulate low-level desired waves near minimum sensitivity, then the reception sensitivity is improved, but the circuit scale and power consumption increase
Solution Approach 1:
The patent applies dynamic gain control by adjusting the gain of the variable gain amplifier based on the detected signal level. When a desired wave near minimum sensitivity is detected, the system dynamically increases the gain to amplify the weak signal for proper demodulation, while returning to normal gain when stronger signals are present, thus avoiding permanent circuit complexity expansion
Solution Approach 2:
The system changes the operational parameters of the receiving device by adjusting the gain parameter of the variable gain amplifier according to signal conditions. This parameter adjustment allows the same circuit to handle both weak desired waves near minimum sensitivity and stronger signals without requiring multiple fixed-gain stages, thereby avoiding increased circuit scale
2Reliability
If the dynamic range is increased to handle strong interfering waves and low-level desired waves, then the demodulation reliability is improved, but the power consumption increases
Solution Approach 1:
The patent implements dynamic power management through conditional gain adjustment. The variable gain amplifier operates at high gain only when weak desired waves near minimum sensitivity are detected alongside strong interfering waves, and returns to standard operation otherwise. This dynamic behavior reduces average power consumption while maintaining demodulation reliability when needed
Solution Approach 2:
The system adjusts the gain parameter of the variable gain amplifier based on detected signal conditions. By changing this parameter dynamically rather than maintaining a fixed high-gain configuration, the system achieves reliable demodulation of low-level desired waves only when necessary, thereby reducing overall power consumption while maintaining demodulation reliability
3Illumination intensity
If the analog gain is increased to amplify low-level desired waves, then the signal level is improved, but the interfering waves cause saturation and distortion
Solution Approach 1:
The patent extracts and processes signals in two separate domains: analog domain for initial amplification and digital domain for final gain adjustment. By converting the amplified analog signal to digital and then applying additional gain control in the digital domain, the system avoids saturating the analog amplification stage with strong interfering waves while still achieving the necessary signal level for demodulation
Solution Approach 2:
The A/D converter acts as an intermediary between the analog variable gain amplifier and the digital variable gain function. This intermediary allows the system to transition from analog to digital processing, enabling gain control in the digital domain where saturation and distortion from strong interfering waves do not occur, thus protecting the analog amplification stage while achieving the required signal level
4Adaptability or versatility
If the circuit scale is expanded to increase dynamic range, then the reception capability is improved, but the device complexity increases
Solution Approach 1:
The patent implements a universal receiving architecture where a single variable gain amplifier and A/D converter handle both weak desired waves near minimum sensitivity and strong signals with interfering waves. By making these components universally applicable through dynamic gain control rather than creating separate dedicated circuits for different signal conditions, the system achieves enhanced reception capability without increasing device complexity
Solution Approach 2:
The system achieves multiple reception capabilities through dynamic operation of existing components rather than through static circuit expansion. The variable gain amplifier and digital signal processing components dynamically adapt to different signal conditions, providing universal reception capability across wide dynamic ranges without requiring multiple fixed-function circuits, thereby avoiding increased device complexity
Data Source
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AI summary
A receiving device performs log noise amplification on radio waves (desired waves and interfering waves), received with an antenna, to generate a received signal, converts the received signal into an intermediate frequency signal, converts the intermediate signal into a digital signal, filters out and demodulates a frequency band of a specific channel from the digital signal. Herein, a first received signal strength (RSSI 1) is detected from the digital signal, while a second received signal strength (RSSI 2) is detected from the digital signal of the specific channel. The intermediate frequency signal is amplified with a first gain which is calculated by way of the comparative judgment on the first receive signal strength and the allowable threshold. The digital signal of the specific channel is amplified with a second gain which is calculated by way of the comparative judgment on the level difference between the first received signal strength and the second received signal strength and the allowable threshold. When the level difference between the first received signal strength and the second received signal strength is smaller than the allowable threshold, the second gain is set to a multiplying factor 1 via multiplication scaling upon determining the nonexistence of interfering waves. Thus, it is possible to reliably receive desired waves, close to the minimum sensitivity, in environments undergoing strong interfering waves, thus demodulating desired waves with an appropriate level.