Pulse-Based UWB Antenna Phase Estimation Using PLL Tracking

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Solution Overview

Problem

Existing ultra-wideband communication systems face challenges in estimating phase shifts between signals from different antennas, carrier frequency offsets, and impulse responses due to desynchronization and multiple reflections, leading to poor demodulation performance and interference.

Innovation Solution

A method for estimating phase and frequency shifts using a phase-locked loop and linear regression on digitized signals from multiple antennas, with guard intervals to suppress interference, and calculating phase differences to determine angular direction and channel impulse response.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If phase and frequency estimation methods based on correlation between squared reception channel I and Q are used, then synchronization can be achieved, but estimation performance deteriorates at low signal-to-noise ratio

Engineering Contradiction:

Improvesynchronization capabilityVSAvoidphase and frequency estimation accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent replaces the mechanical operation of squaring the reception signals with a correlation-based estimation method. Instead of computing I² and Q² and correlating them, the invention directly correlates the I and Q channels to estimate phase and frequency shifts, avoiding the noise-amplifying squaring operation while maintaining synchronization capability

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the estimation parameters from second-order statistics (squared signals) to first-order statistics (direct signal correlation). By using the correlation between I and Q channels directly rather than their squares, the method achieves better noise performance and estimation accuracy at low signal-to-noise ratios

Inventive Principle:

Principle #35Parameter changes

2Productivity

If signals from multiple antennas are received simultaneously without separation, then communication throughput is improved, but phase shift estimation becomes difficult due to signal mixing

Engineering Contradiction:

Improvecommunication throughputVSAvoidphase shift estimation difficulty

Core Design Contradiction:

ProductivityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent segments the received signal into distinct components corresponding to each transmitting antenna. By identifying and separating the signal contributions from different antennas through correlation-based estimation, the system can estimate phase shifts for each antenna individually even when signals are received simultaneously, thus maintaining both throughput and estimation accuracy

Inventive Principle:

Principle #1Segmentation

3Reliability

If guard intervals are inserted between segments to suppress interference, then intersymbol interference is reduced, but transmission time increases

Engineering Contradiction:

Improvesignal qualityVSAvoidtransmission time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies partial action by using correlation-based estimation that can operate effectively with reduced or optimized guard intervals. The method does not require complete signal separation that would demand excessive guard times,而是 uses the correlation property to extract phase and frequency information even with shorter guard intervals, thus reducing time loss while maintaining signal quality

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentEP4105673B1Method for estimating characteristics of a pulse-based ultra-wideband signal emitted by a plurality of antennas

Publication Date: 2025.09.17 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES

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AI summary

A method for estimating at least one characteristic of a signal received by a receiver, the signal having been emitted successively by several antennas in successive time segments, each segment being dedicated to a distinct antenna, the signal being pulse-modulated using ultra-wideband modulation, the method comprising the steps of: - Receiving and digitizing said signal, - Calculating (503) the product of each symbol of the received signal with the complex conjugate of the corresponding emitted symbol, - For each segment and for each symbol of the signal received for that segment, estimating a phase error by means of a phase-locked loop (504) applied to said product, - For each segment, determining (505) a reference phase by means of a linear regression applied to the phase errors estimated over all segments, - Determining (506), for at least one pair of antennas,a phase difference between the signals emitted by the antennas of the pair, based on the difference between the reference phases calculated for the segments associated with said antennas.