Preemptive AGC for Receiver Saturation From RF Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wireless communication receivers in portable devices face saturation and interference issues when collocated or external transmitting components start their transmission after the automatic gain control (AGC) gain has been set, leading to potential signal loss or corruption.
Innovation Solution
A preemptive automatic gain control (AGC) system that dynamically adjusts the gain setting based on real-time detection of interfering signals, including their frequency, power, and transmission time, to generate an interference-free signal by enabling or disabling the preemptive AGC component and switching to AGC mode as necessary, ensuring the signal strength meets a minimum detectable signal threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the AGC gain is set based on the desired signal during the preamble, then the dynamic receiver range is maximized and quantization noise is minimized, but the receiver becomes saturated or blocked when interfering signals are transmitted after the gain is set
Solution Approach 1:
The patent performs preliminary detection of interfering signals during the preamble period before the actual data transmission. By detecting the presence and characteristics of interfering signals in advance, the system can preemptively adjust the AGC gain setting to prevent receiver saturation when the interfering signals become active, while still maintaining optimal quantization performance for the desired signal.
Solution Approach 2:
The system implements a feedback mechanism where the detected interfering signal characteristics (power level, frequency, timing) are used to dynamically adjust the AGC gain setting. This closed-loop approach allows the receiver to continuously adapt to changing interference conditions and maintain optimal performance without saturation.
2Reliability
If the AGC amplifies the received signal to ensure it is not clipped, then the signal quality is maintained, but the receiver cannot handle strong interfering signals that cause saturation
Solution Approach 1:
The patent applies preliminary anti-action by detecting interfering signals during the preamble and preemptively reducing the AGC gain before the interfering signals cause saturation. This preventive measure counteracts the harmful effect of strong interfering signals by adjusting the gain in advance, allowing the receiver to handle both weak desired signals and strong interfering signals simultaneously without clipping or saturation.
3Device complexity
If the receiver uses a fixed AGC gain setting, then the system complexity is reduced, but the receiver cannot dynamically adapt to changing interference conditions
Solution Approach 1:
The patent performs preliminary detection of interfering signals during the preamble period and uses this information to set an appropriate AGC gain before data transmission begins. This preliminary action allows the system to maintain a relatively simple fixed-gain architecture during data transmission while still achieving dynamic adaptation through the initial detection and gain setting phase.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Described herein are technologies related to an implementation of interference mitigation in a receiver of a portable device. A preemptive - automatic gain control (AGC) system mitigates a collocated or external interfering signal in a receiver of a portable device. The receiver of the portable device receives and processes a data packet of a first radio frequency (RF) signal that includes a Bluetooth (BT) signal, a Wi-Fi signal, a near field communications (NFC), 3G, 4G, or the like. During the processing of the data packet, a collocated or an external second RF signal is detected and received by the receiver. The second RF signal includes an interfering Bluetooth (BT) uplink transmission, a near field communications (NFC) transmission signal, a Wi-Fi transmission signal, 3G or 4G uplink transmission, an LTE signal, or the like.