Universal IR Receiver Circuit Carrier Frequency Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Universal infrared (IR) receivers face challenges in determining the carrier frequency and decoding IR signals simultaneously, especially when the carrier frequency and encoding methods are unknown, as they require separate circuitry and time for carrier frequency determination, which increases complexity and power consumption.
Innovation Solution
A system and method using a single circuitry with a switching element, edge detector, adjustable clock, and counter to concurrently detect the carrier frequency and decode IR signals by adjusting the clock frequency for sampling and refining the frequency comparison, allowing the same circuitry to tune the demodulator and band-pass filter upon determining the carrier frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate circuitry is used for carrier frequency determination and signal decoding, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent combines carrier frequency determination and signal decoding functions into a single universal receiver circuit. The same circuitry that decodes the signal also determines carrier frequency by measuring the period of the carrier wave during the signal reception process, eliminating the need for separate dedicated frequency measurement circuitry.
Solution Approach 2:
The receiver circuit is designed to perform multiple functions: it simultaneously decodes the incoming signal and measures the carrier frequency. The circuit can operate in different modes (decoding mode and frequency measurement mode) using the same hardware components, making the system universal and adaptable to different signal types.
2Measurement precision
If separate circuitry is used for carrier frequency determination and signal decoding, then measurement precision is improved, but power consumption increases
Solution Approach 1:
The patent merges carrier frequency determination and signal decoding into a single operational process using the same circuitry. By measuring the carrier period during the natural signal reception and decoding process, the system avoids the continuous operation of separate frequency measurement circuits, thereby reducing overall power consumption.
Solution Approach 2:
The carrier frequency measurement is performed periodically during signal reception by measuring the period of incoming carrier waves. This periodic measurement approach allows the system to obtain frequency information only when needed (during signal reception), rather than continuously, thus reducing power consumption.
3Measurement precision
If carrier frequency determination is performed before signal decoding, then measurement precision is improved, but loss of time increases
Solution Approach 1:
The system performs preliminary carrier frequency measurement during the preamble or initial portion of the signal reception. By measuring the carrier period in advance during the natural signal structure, the system prepares frequency information before full decoding begins, minimizing additional time requirements.
Solution Approach 2:
The patent enables continuous operation where the same circuitry seamlessly transitions between carrier frequency measurement and signal decoding without interruption. The frequency measurement occurs during the signal reception process itself, maintaining continuous useful action and avoiding idle time between measurement and decoding operations.
Data Source
AI summary
Consumer infrared (CIR) systems typically are used in remote control systems. Most CIR systems expect a known carrier frequency and encoding scheme. However, there are many applications of a universal CIR receiver which can receive and decode CIR signals regardless of the carrier frequency or encoding scheme. A CIR receiver circuit is disclosed which can both decompose a received CIR signal into run length representation and detect the carrier frequency. The result can then be supplied to a host device for further processing, interpretation and/or actions.