Wireless Device Radar Distance Estimation Using Channel Impulse Response
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Solution Overview
Problem
Current vehicular radar systems are costly to manufacture, spectrally inefficient, lack multiple access capabilities, and are insecure, making them expensive to implement and prone to disruptions in emergency braking and adaptive cruise control systems.
Innovation Solution
A method and system using wireless devices, such as IEEE 802.11 devices, to estimate target distance by transmitting a waveform, receiving reflections, obtaining a channel impulse response, and applying a parameterized function to measure the distance, which reduces the need for high-cost radar hardware and improves spectral efficiency and security.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional vehicular radar systems are used, then distance measurement capability is achieved, but manufacturing cost increases due to tightly-coupled analog circuits and advanced antenna configurations
Solution Approach 1:
The patent uses wireless communication signals (such as WiFi) as a copy or alternative to traditional radar electromagnetic waves. Instead of using dedicated radar hardware with expensive analog circuits and antenna configurations, the system repurposes existing wireless communication infrastructure to perform distance measurement through signal reflection and time-of-flight calculation, thereby reducing manufacturing cost while maintaining measurement capability
Solution Approach 2:
The patent makes wireless communication devices serve dual functions: both data communication and radar-like distance measurement. By enabling wireless devices to operate as radar devices, the system eliminates the need for separate dedicated radar hardware, reducing cost and complexity while achieving the same distance measurement function
2Measurement precision
If traditional radar systems are used, then distance measurement is achieved, but spectral efficiency deteriorates due to large bandwidth requirements
Solution Approach 1:
The patent changes the fundamental parameters of the measurement system by using existing wireless communication bandwidths (e.g., 20 MHz for WiFi) instead of requiring the large bandwidths (150 MHz) that traditional radar needs for meter-level accuracy. This parameter change allows distance measurement to be achieved with significantly improved spectral efficiency by leveraging the already allocated wireless spectrum
3Measurement precision
If traditional radar systems are used, then distance measurement capability is provided, but security deteriorates due to susceptibility to spoofing
Solution Approach 1:
The patent incorporates feedback mechanisms through the wireless communication protocol's built-in verification and authentication systems. The two-way communication and signal exchange required for distance measurement in wireless networks provide inherent feedback loops that can verify signal integrity and detect spoofing attempts, thereby improving security compared to one-way radar transmissions
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
This approach achieves higher accuracy in target range estimation with less spectrum bandwidth, reduces implementation costs, and enhances security compared to traditional radar systems, making it suitable for vehicular applications.
Implementation Method 1
A radar transmits radio waves or microwaves that reflect from any object in their path. A receive radar, which is typically the same system as the transmit radar, receives and processes these reflected waves to determine properties of the object(s).
Data Source
AI summary
A method, system and computer program product for computing a target distance estimate using a wireless device. A waveform is transmitted to an object (e.g., automobile) by a wireless device. Reflections of the waveform are then received, such as on two forward directional antennas. A channel impulse response (e.g., a frequency-domain channel impulse response) is then obtained from the reflections. A parameterized function is applied to the channel impulse response. Parameters of the parameterized function are fitted to measure the channel impulse response. A distance to the object is then estimated based on the fitted parameters. In this manner, by operating wireless devices as radar devices, a higher accuracy in target range estimates can be achieved with less spectrum bandwidth when compared to standard radar waveforms with standard radar processing. Furthermore, by utilizing wireless devices as opposed to radar devices, the cost problem associated with radar is addressed.