Synchronized Radio Receivers for Time Difference of Arrival Direction Finding

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Solution Overview

Problem

Time domain cellular radio networks face challenges in efficiently detecting and locating interfering signals due to the periodic switching between uplink and downlink time slots, making it a time-consuming process.

Innovation Solution

A method and device for timeslot-wise detection of radio signals, where signals received by two antennas are processed by synchronized radio receivers, allowing for the selection of a specific time slot and calculation of time difference of arrival to derive directional information, facilitating faster location of signal emitters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If direction finding is performed by manually searching for maximum signal level while altering position, then directional information can be obtained, but the process becomes time-consuming and requires high efforts

Engineering Contradiction:
Improvedirectional information accuracyVSAvoidtime for locating emitter
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces the mechanical manual position-altering method with an electronic signal processing system. Instead of physically moving to find maximum signal level, the system uses synchronized receivers at fixed positions with electronic time difference calculation to determine direction, thereby eliminating time-consuming manual searching while maintaining directional accuracy

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces timing information as an intermediary element. By measuring the time difference of arrival of signals at synchronized receivers and using this timing data to calculate direction, the system avoids direct manual position searching while achieving accurate directional information

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If direction finding is performed in a time domain cellular radio network with periodic uplink and downlink switching, then signal detection is possible, but the process becomes specifically time-consuming

Engineering Contradiction:
Improvesignal detection capabilityVSAvoidtime for emitter location
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary synchronization to the receivers before signal detection. By pre-synchronizing the receivers with the periodic frame structure of the time domain network, the system is prepared to immediately detect and time-stamp signals when they arrive, eliminating the need to wait for or adapt to each periodic switching cycle, thus reducing detection time while maintaining reliability

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent utilizes the periodic frame structure of the time domain cellular radio network by synchronizing receivers to this periodic pattern. This allows the system to efficiently detect signals during appropriate time slots (uplink or downlink) without being disrupted by the periodic switching, thereby maintaining reliable detection while minimizing time loss

Inventive Principle:
Principle #19Periodic action

3Measurement precision

If manual position alteration is used to vary relative orientation with respect to the emitter, then directional information can be obtained, but the required efforts are high due to reflections causing misrouting

Engineering Contradiction:
Improveemitter location accuracyVSAvoidoperational complexity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent replaces manual position alteration with a stationary multi-receiver system that uses signal processing to determine direction. By keeping receivers fixed and using electronic time difference calculation, the system eliminates the operational complexity of manual position changes and their associated problems with reflections and misrouting, while maintaining accurate emitter location capability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses timing information as an intermediary to determine direction without requiring physical movement. By measuring the time difference of arrival at fixed receivers and calculating direction from this data, the system avoids the operational complexities of manual position alteration and reflection-related misrouting while achieving accurate emitter location

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3690472B1Method as well as device for timeslot-wise detection of at least one radio signal
Publication Date: 2021.10.20 ROHDE & SCHWARZ GMBH & CO KG
  • EP3690472B1 patent drawingFigure 1~2
  • EP3690472B1 patent drawingFigure 3~5

AI summary

A method of timeslot-wise detection of at least one radio signal in a cellular radio network. A radio signal is received via at least one first radio antenna (16) and at least one second radio antenna (20). The radio signal received by the respective radio antennas (16, 20) is forwarded to at least one first radio receiver (14) assigned to the first radio antenna (16) and to at least one second radio receiver (18) assigned to the second radio antenna (20). The radio signal forwarded is evaluated. The radio receivers (14, 18) are synchronized with a preconfigured frame structure. At least one identical time slot is selected out of the frame structure. Timing information of the selected time slot is provided from the first radio receiver (14) to the second radio receiver (18), from the second radio receiver (18) to the first radio receiver (14) and/or from the respective radio receiver (14, 18) to a central unit for calculating a time difference of arrival. Further, a device (10) for timeslot-wise detection is described.