Chirp-Modulated Ranging for IoT Node Localization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing communication systems for IoT networks face challenges in providing low power, spectral efficiency, and precise positioning for both stationary and moving objects, especially in scenarios with limited radio bandwidth and high node density, where energy efficiency and computation complexity are critical.
Innovation Solution
A wireless communication network using chirp-modulated radio signals with continuous phase functions, where nodes can synchronize their time references through ranging requests and responses, allowing for precise positioning and enhanced localization using antenna, frequency, and time diversity, both in the network infrastructure and mobile nodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If narrow-band or ultra-narrow band modulation is used to achieve spectral efficiency, then bandwidth usage is optimized, but synchronization precision between transmitter and receiver becomes extremely demanding
Solution Approach 1:
The patent applies preliminary action by implementing a preamble sequence before the actual data transmission in the NarrowBand uplink protocol. This preamble contains synchronization signals that enable the receiver to perform time and frequency synchronization before the main data arrives, thus preparing the system in advance to handle the precision requirements of narrow-band modulation without compromising data transmission efficiency
Solution Approach 2:
The patent uses reference signals as intermediaries between the transmitted data and the receiver's detection process. These reference signals are inserted at specific positions in the time-frequency grid and serve as mediators that help the receiver achieve precise synchronization and channel estimation, bridging the gap between the narrow-band signal constraints and the precision requirements
2Reliability
If existing IoT communication systems are used, then basic connectivity is achieved, but energy efficiency and computation complexity are insufficient for battery-operated devices with limited resources
Solution Approach 1:
The patent applies parameter changes by introducing scalable modulation schemes (QPSK, 16-QAM, 64-QAM) and configurable transmission parameters such as payload size, repetition factor, and coding rate. These parameters can be dynamically adjusted based on channel conditions and device capabilities, allowing battery-operated devices to optimize their energy consumption by selecting appropriate transmission parameters rather than using fixed high-power modes
Solution Approach 2:
The patent implements partial action through the NarrowBand uplink design where devices can transmit with reduced power and bandwidth compared to full LTE uplink. The system allows devices to send small payloads with lower complexity modulation, performing only the necessary communication function rather than full-capacity transmission, thus reducing energy consumption while maintaining basic connectivity reliability
Data Source
Figure 1~2c
Figure 3~5
Figure 6
AI summary
A wireless communication method in a network comprising a plurality of nodes (523, 510) including ranging masters (A), broadcasting a chirp-modulated ranging requests (543), and ranging slaves slave (B), replying with thereto with chirp-modulated ranging responses (545), whereby mobile nodes (E, 510) can locate themselves passively by listening to the request/reply exchanges, based on the respective time differences of arrival.