Vehicle Power-Line Communication Using DSSS Against Interference
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Solution Overview
Problem
Existing communication systems in vehicles, such as CAN and LIN, face challenges with bulkiness, complexity, and increased installation effort due to separate signal lines, and power-line communication methods suffer from interference and noise issues, particularly with increasing autonomy and the need for more cameras and sensors.
Innovation Solution
A spread spectrum method using direct sequence spread spectrum (DSSS) with a Barker code for modulating signals over a common power supply line, distributing transmission power across a broad spectrum to reduce interference susceptibility and lower power output, allowing for robust and rapid data exchange.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate signal lines are used for communication between devices, then communication reliability is improved, but device complexity and installation effort increase
Solution Approach 1:
The patent combines power supply and communication functions into a single power supply line. The power supply line serves dual purposes: delivering electrical power to devices and transmitting communication signals through voltage modulations, thereby eliminating the need for separate signal lines and reducing installation complexity while maintaining communication reliability
Solution Approach 2:
The power supply line is designed to perform multiple functions simultaneously. It acts as both an electrical power delivery medium and a communication channel, allowing the same infrastructure to support both energy supply and data transmission between devices in the vehicle
2Ease of manufacture
If power supply lines are used for communication, then installation effort is reduced, but interference susceptibility increases
Solution Approach 1:
The patent converts the inherently noisy power supply environment into an advantage by using spread spectrum modulation. The wide bandwidth available in power supply lines, which normally carries noise, is utilized to distribute signal energy across multiple frequencies, making the communication more robust against narrowband interference and noise through spectral spreading
Solution Approach 2:
The patent changes the modulation parameters by using spread spectrum techniques with wide bandwidth modulation instead of narrowband modulation. This parameter change distributes the signal power across a wide frequency range, reducing the impact of narrowband interference and improving signal detection reliability in noisy power supply environments
3Power
If narrowband modulation is used for power-line communication, then power output is concentrated, but interference susceptibility increases
Solution Approach 1:
The patent changes the modulation parameters from narrowband to wideband spread spectrum modulation. By spreading the signal energy across a wide frequency spectrum, the power concentration at any single frequency is reduced, which decreases susceptibility to narrowband interference while maintaining overall transmission effectiveness through integrated power across the broad spectrum
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
The solution enables communication that matches the performance of established bus systems while being robust against interference, reducing structural space and installation complexity, and improving electromagnetic compatibility.
Implementation Method 1
a spread spectrum method is used for communication purposes. The invention is based on the concept of additionally modulating the wanted signals to be transmitted as narrowband modulations of a carrier signal and so enlarging the bandwidth thereof.
Implementation Method 2
In the DSSS method the wanted signal is spread by means of a pre-determined bitstring, the 'spreading code', such that the bits of the original bit string of the wanted signal are translated into a plurality of sub-bits, or chips.
Implementation Method 3
a Barker code is preferably used as the spreading code, in particular a Barker code of length 7. Barker codes are binary codes with minimum autocorrelation on shifting, such that the signals spread therewith have low cross-correlation with narrowband interference signals
Implementation Method 4
The transmitter sends the signal as voltage modulation via the power supply in an asynchronous method
Data Source
AI summary
A method and a modem for communication between at least two devices (10) of a vehicle. The devices (10) communicate with each other via a common power supply line (1). A frequency spread method is used for communication.