UWB Communication With Cyclically Shifted Codes for AoA/AoD

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Solution Overview

Problem

Existing UWB communication systems face challenges in determining the angle of arrival (AoA) and angle of departure (AoD) of radio-frequency waves, which limits the precision of localization systems.

Innovation Solution

A communication system that utilizes UWB transmitters transmitting packets with predefined codes, including cyclically shifted versions, allowing for simultaneous transmission of packets, thereby enabling precise determination of AoA and AoD without increasing airtime.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple UWB transmitters transmit packets sequentially to enable AoA and AoD determination, then measurement precision is improved, but airtime increases

Engineering Contradiction:
ImproveAoA and AoD determination precisionVSAvoidairtime
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent merges multiple sequential transmissions into a single simultaneous transmission by combining multiple packets with different cyclically shifted codes into one transmission slot. This allows the receiver to process multiple signals at once, achieving AoA and AoD determination without extending airtime, thus resolving the contradiction between measurement precision and time loss.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent employs periodic cyclically shifted codes in the packet structure, where each transmitter uses a distinct cyclic shift of a base code. This periodic structure enables the receiver to differentiate between simultaneous transmissions from multiple transmitters through correlation processing, allowing precise angle determination while maintaining efficient time usage.

Inventive Principle:
Principle #19Periodic action

2Productivity

If multiple UWB transmitters transmit packets simultaneously with the same code, then airtime is reduced, but signal differentiation becomes impossible

Engineering Contradiction:
Improvetransmission efficiencyVSAvoidsignal identification capability
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent applies local quality by assigning distinct cyclically shifted codes to different transmitters while maintaining the same base code structure. Each transmitter's signal has a unique local characteristic (specific cyclic shift value) that enables the receiver to differentiate and identify individual signals even during simultaneous transmission, thus preserving signal identification capability while improving transmission efficiency.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the temporal parameter of the code structure by applying different cyclic shifts to the base code for each transmitter. This parameter change (cyclic shift amount) creates distinguishable signal characteristics without requiring different base codes, enabling simultaneous transmission differentiation while maintaining code efficiency and reducing airtime.

Inventive Principle:
Principle #35Parameter changes

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 system achieves reduced airtime and maintains localization accuracy by allowing simultaneous transmission of packets with distinct codes, facilitating precise AoA and AoD determination.

Implementation Method 1

a first UWB transmitter (102) configured to be coupled to a first antenna (104)... a second UWB transmitter (106) configured to be coupled to a second antenna (108)... transmitting packets with predefined codes

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 2

a processing unit (304) configured to correlate at least a first packet and a second packet received by the UWB receiver (302) with a predefined code

Methodology Applied
Scientific EffectSignal correlation:

Data Source

PatentEP4231039B1Communication system, communication device, methods of operation and computer programs
Publication Date: 2025.09.10 NXP BV
  • EP4231039B1 patent drawingFigure 1A
  • EP4231039B1 patent drawingFigure 1B
  • EP4231039B1 patent drawingFigure 2A~2B

AI summary

In accordance with an aspect of the present disclosure, a communication system is provided, comprising: a first ultra-wideband (UWB) transmitter configured to be coupled to a first antenna; a second UWB transmitter configured to be coupled to a second antenna; a controller configured to cause the first UWB transmitter to transmit a first packet to an external communication device, wherein the first packet contains a predefined code; wherein the controller is further configured to cause the second UWB transmitter to transmit a second packet to the external communication device, wherein the second packet contains a cyclically shifted version of said predefined code. In accordance with another aspect of the present disclosure, a communication device is provided, comprising: an ultra-wideband (UWB) receiver configured to be coupled to an antenna, wherein the UWB receiver is further configured to receive at least a first packet and a second packet from an external communication system, wherein the first packet contains a predefined code and the second packet contains a cyclically shifted version of said predefined code; a processing unit configured to correlate the first packet and the second packet received by the UWB receiver with the predefined code. In accordance with further aspects, corresponding methods of operation are conceived, as well as computer programs for carrying out said methods.