CP-OFDM RF Sensing With Multiple-Hypothesis Receive Processing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional orthogonal frequency-division multiplexing (OFDM) communication schemes using a cyclic prefix (CP-OFDM) face challenges in achieving high maximum target ranges and maximum target Dopplers for RF sensing, particularly in automotive applications due to limited CP duration and insufficient subcarrier spacing.
Innovation Solution
Implementing a multiple hypothesis testing (MHT) algorithm for receive processing of the CP-OFDM waveform to enhance RF sensing performance, allowing it to meet key performance indicators (KPIs) that are otherwise unattainable with CP-OFDM.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional CP-OFDM is used for RF sensing, then communication compatibility is maintained, but maximum target range and maximum target Doppler performance are insufficient
Solution Approach 1:
The patent applies parameter changes by modifying the receive processing parameters (testing hypotheses across different time delays and Doppler shifts) to transform CP-OFDM into a sensing-capable system. This allows the existing CP-OFDM waveform to achieve radar-like sensing performance without changing the fundamental communication protocol, thereby improving RF sensing performance while maintaining communication compatibility.
Solution Approach 2:
The patent introduces multiple hypothesis testing as an intermediary processing layer between the received CP-OFDM signal and the final sensing output. This intermediary mechanism enables the system to extract sensing information (target range, Doppler, velocity) from communication signals by testing multiple possible scenarios, thus bridging the gap between communication and sensing functions.
2Reliability
If CP duration is increased to improve maximum target range, then sensing performance improves, but communication overhead increases
Solution Approach 1:
The patent changes the interpretation and processing parameters of the existing cyclic prefix rather than increasing its duration. By applying multiple hypothesis testing to the received signal across different time delay hypotheses, the system can achieve extended maximum target range detection without actually increasing the CP duration, thus avoiding additional communication overhead while improving sensing performance.
3Reliability
If subcarrier spacing is increased to improve maximum target Doppler, then sensing performance improves, but communication spectral efficiency decreases
Solution Approach 1:
The patent applies parameter changes in the signal processing domain rather than the physical waveform domain. By using multiple hypothesis testing with different Doppler shift hypotheses, the system can detect higher maximum target Doppler frequencies without actually increasing the subcarrier spacing, thereby maintaining spectral efficiency while achieving improved Doppler detection capability.
4Reliability
If multiple hypothesis testing is implemented, then RF sensing KPIs are achieved, but processing complexity increases
Solution Approach 1:
The patent segments the hypothesis testing process into discrete, manageable steps: generating hypotheses for different time delays and Doppler shifts, computing correlation metrics for each hypothesis, and selecting the maximum. This segmentation makes the complex processing more systematic and implementable, balancing sensing accuracy with processing complexity by breaking down the MHT algorithm into structured operations.
Data Source
AI summary
Embodiments described herein provide for using a cyclic prefix orthogonal frequency-division multiplexing (CP-OFDM) waveform for radio frequency (RF) sensing by providing a novel receive processing, which may include a multiple hypothesis testing (MHT) algorithm, to allow the CP-OFDM waveform to achieve certain RF sensing key performance indicators (KPIs), such as maximum target ranges and maximum target Dopplers, that are otherwise unavailable with CP-OFDM. Embodiments herein may be used in monostatic configurations and may allow CP-OFDM to meet KPIs for automotive applications. The appendices attached hereto provide additional details regarding various embodiments.