Transmitter Receiver Wireless Control Interference
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Solution Overview
Problem
Wireless communication systems using IEEE 802.11 in the ISM band face challenges in precisely controlling radio apparatuses due to interference waves from other channels, leading to failure in transitioning from sleep mode to active mode.
Innovation Solution
A transmitter and receiver system that performs carrier sensing in a desired frequency band, transmitting radio frames with specific time intervals representing an identifier only when the wireless communication space is available, and waiting to transmit when it is not, ensuring accurate control even with interference waves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If carrier sensing is performed in a broad frequency band to cover all ISM channels, then the system can detect interference from other channels, but the receiver cannot precisely identify the intended transmitter due to interference waves
Solution Approach 1:
The patent segments the broad frequency band into multiple individual frequency channels. The receiver performs carrier sensing on each channel separately and identifies the intended transmitter by detecting which specific channel contains the targeted radio frames with matching identifiers, rather than processing all channels simultaneously as a single broad band.
Solution Approach 2:
The patent introduces identifier matching as an intermediary verification step between carrier sensing and transmitter identification. The receiver uses the identifier in the radio frame payload as a mediator to confirm whether a detected signal on a specific channel is from the intended transmitter, filtering out interference from other channels.
2Device complexity
If the receiver uses envelope detection to simplify circuitry and reduce power consumption, then the receiver can operate with lower complexity, but the receiver cannot perform synchronous detection to accurately demodulate and decode wireless LAN frames
Solution Approach 1:
The patent applies partial synchronous detection by performing carrier sensing and identifier matching only on specific frequency channels where the intended transmitter operates, rather than fully demodulating and decoding all received wireless LAN frames. This partial action achieves sufficient precision for the control function while maintaining low circuit complexity.
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
Enables precise control of radio apparatuses by ensuring that the time intervals between detection timings of radio frames match the identifier, allowing the system to function correctly even in the presence of interference waves.
Implementation Method 1
a carrier sensing unit performing carrier sensing in a desired frequency band including a plurality of frequency channels
Implementation Method 2
transmits, in the desired frequency band, one radio frame such that a time interval between detection timings of a radio frame in a radio apparatus of a receiver constitutes one or more of one or more signal detection intervals representing an identifier
Implementation Method 3
signals that have been band-limited by an RF filter are received using envelope detection, which is a type of asynchronous detection, in order to simplify its circuitry and process and to reduce power consumption
Implementation Method 4
signals that have been band-limited by an RF filter are received
Data Source
AI summary
A receiver has an ID that includes three signal detection intervals (S1, S2, S3). The three signal detection intervals (S1, S2, S3) are detected as the receiver detects a signal consisting of a value larger than a threshold at each of the detection timings (DT1 to DT4). The transmitter transmits four radio frames (FR1 to FR4) such that each of the radio frames straddles the corresponding one of the detection timings (DT1 to DT4) in the receiver.