Transmitter Localization Using Modulo Phase Differences in Motion
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Solution Overview
Problem
Existing techniques for estimating the location of a transmitter using phase differences are not satisfactory in certain situations, particularly when receivers are in motion relative to the transmitter, and do not provide accurate results.
Innovation Solution
The location of a transmitter is estimated by determining phase differences between signals received at multiple receivers, with a modulo technique used to ensure the phase differences correspond to the same cycle of the signal envelope, allowing for increased separation between receivers to improve accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If receivers are placed closer together to maintain synchronization when in motion, then reliability of location estimation is improved, but measurement precision deteriorates due to reduced separation between receivers
Solution Approach 1:
The patent introduces a modulo technique as an intermediary method to resolve the phase ambiguity problem. By applying modulo arithmetic to the phase differences, the system can correctly identify the integer number of cycles between receivers, thereby maintaining measurement precision even when receivers are in motion and separated by larger distances.
Solution Approach 2:
The patent changes the parameter of receiver separation distance, allowing receivers to be placed farther apart to improve measurement precision. The modulo technique compensates for the motion-induced phase changes, enabling the system to maintain reliability while increasing the baseline distance between receivers for better angular resolution.
2Measurement precision
If receivers are separated by large distances to improve location estimation accuracy, then measurement precision is improved, but difficulty of detecting and measuring worsens due to phase cycle ambiguity
Solution Approach 1:
The modulo technique serves as an intermediary computational method that resolves the phase cycle ambiguity. By using modulo arithmetic on the measured phase differences, the system can determine the correct integer number of cycles between receivers, making it feasible to use large separations without losing measurement capability.
3Adaptability or versatility
If receivers are in motion relative to the transmitter to enable dynamic detection, then adaptability is improved, but measurement precision deteriorates due to changing phase relationships
Solution Approach 1:
The patent embraces the dynamic nature of moving receivers by developing a method that explicitly accounts for motion-induced phase changes. The modulo technique is applied to the time-varying phase differences, allowing the system to maintain measurement precision despite the changing geometric relationships between receivers and transmitter.
Solution Approach 2:
The modulo arithmetic operation acts as an intermediary that corrects for the dynamic phase changes caused by receiver motion, enabling precise location estimation even when receivers are moving relative to the transmitter.
Data Source
AI summary
The location of a transmitter transmitting a signal may be estimated by receiving the signal at each receiver of a plurality of receivers, where the receivers are in motion relative to the transmitter. The following are performed for pairs of receivers to yield phase differences: establishing a first phase offset of the signal as received at a first receiver; establishing a second phase offset of the signal as received at a second receiver; and determining a phase difference corresponding to the pair of receivers in accordance with the first phase offset and the second phase offset. A location of the transmitter is estimated in accordance with the plurality of phase differences.