Chirped Sine Wave Delay Calibration for Base Station Timing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current base station technologies require complex and time-consuming delay calibration processes, especially after factory repairs, and are prone to timing errors due to component aging and environmental changes, necessitating the storage of extensive calibration data.

Innovation Solution

The system measures end-to-end data path delays using chirped sine waves transmitted over asynchronous communication networks, allowing the Radio Equipment (RE) to automatically recompute processing delays and eliminate the need for stored calibration data, enabling precise timing alignment without manual recalibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional delay calibration methods are used, then timing alignment can be achieved, but the process becomes complex and time-consuming, especially after factory repairs

Engineering Contradiction:
Improvetiming alignment precisionVSAvoidcalibration time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs automatic delay calibration by having the RE generate test signals and the REC measure the delays autonomously. This self-calibrating mechanism eliminates the need for manual intervention during factory repairs or field operations, resolving the contradiction between achieving precise timing alignment and minimizing calibration time.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention changes the calibration approach from storing pre-determined delay values to dynamically measuring and computing delays based on actual signal transmission characteristics. By using correlation-based measurement of test signals and adapting delay compensation parameters in real-time, the system achieves both precision and speed in timing alignment.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If extensive calibration data is stored for each radio, then timing alignment can be maintained, but device complexity and storage requirements increase

Engineering Contradiction:
Improvetiming alignment reliabilityVSAvoidcalibration data storage complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts the delay measurement process from pre-stored calibration data and performs it dynamically using actual signal transmission. By measuring delays through correlation of test signals in real-time, the system eliminates the need for extensive pre-calibrated lookup tables, reducing device complexity while maintaining timing alignment reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system implements a feedback mechanism where the REC measures the actual delay of test signals from the RE and communicates the measured delay back to the RE for compensation. This closed-loop feedback approach ensures reliable timing alignment without requiring extensive pre-stored calibration data, as the system continuously adapts to actual transmission conditions.

Inventive Principle:
Principle #23Feedback

3Reliability

If manual recalibration is performed after factory repairs, then timing errors can be corrected, but the process is complex and time-consuming

Engineering Contradiction:
Improvetiming synchronization reliabilityVSAvoidrecalibration ease
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The automatic delay calibration system enables radios to self-calibrate without manual intervention. After factory repairs or during field operations, the RE autonomously generates test signals and the REC automatically measures and communicates the delays, allowing the system to self-correct timing errors without requiring complex manual recalibration procedures.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention replaces manual mechanical calibration procedures with an automated electronic measurement and communication system. By using digital signal processing and automated delay measurement through correlation algorithms, the system eliminates the need for time-consuming manual recalibration while maintaining high timing synchronization reliability.

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

4Measurement precision

If delay calibration is performed frequently to account for component aging and environmental changes, then timing accuracy is maintained, but maintenance costs and time increase

Engineering Contradiction:
Improvetiming accuracyVSAvoidmaintenance time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system continuously measures delay using background test signals rather than performing discrete calibration operations. By continuously monitoring the delay through correlation of ongoing test signals and continuously adjusting compensation parameters, the system maintains timing accuracy without requiring periodic maintenance interruptions, thus eliminating the trade-off between accuracy and maintenance time.

Inventive Principle:
Principle #20Continuity of useful action

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

This approach ensures accurate and automatic timing alignment, reducing maintenance costs and time, and providing current processing delay information for troubleshooting, while avoiding the need for extensive data storage and recalibration.

Implementation Method 1

The REC is configured to correlate a reference chirped sine wave signal and a received signal from the RE on the uplink data path via an asynchronous communication network, where the received signal from the RE includes the uplink chirped sine wave signal. The REC is further configured to determine an uplink data path delay from the RE to the REC based on results of the correlation.

Methodology Applied
Scientific EffectChirp waveform correlation:

Data Source

PatentEP3143808B1Technique to align frame timing of remote cellular radio elements with the data frame timing reference of radio element
Publication Date: 2019.10.02 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3143808B1 patent drawingFigure 1~2
  • EP3143808B1 patent drawingFigure 3
  • EP3143808B1 patent drawingFigure 4

AI summary

Systems and methods for measuring end-to-end data path delays between a Radio Equipment Controller (REC) and a Radio Equipment (RE) of a base station are disclosed. In one embodiment, a system includes a RE configured to transmit an uplink chirped sine wave signal from the RE to a REC on an uplink data path from the RE to the REC via an asynchronous communication network. The REC is configured to correlate a reference chirped sine wave signal and a received signal from the RE. The REC is further configured to determine an uplink data path delay from the RE to the REC based on results of the correlation of the reference chirped sine wave signal and the received signal from the RE on the uplink data path. In another embodiment, a downlink data path delay is measured in a similar manner.