How It Works

Which Delivers Greater Accuracy?

At Metirionic, we specialize in cutting-edge wireless positioning technologies, leveraging Bluetooth Channel Sounding to achieve precise distance measurement. A key factor in determining accuracy is the choice of ranging algorithm. While Phase-Based Ranging (PBR), as referenced by the Bluetooth SIG, provides reliable results in clear line-of-sight conditions, it struggles in environments with multipath interference. Channel Impulse Response (CIR)-based methods, such as our Metirionic Advanced Ranging Stack (MARS), overcome these limitations by reconstructing the full signal path, enabling superior accuracy and robustness in complex environments.

To learn more about the advantages of CIR-based ranging and how it compares to PBR, explore our in-depth article:
Bluetooth Channel Sounding: PBR vs. CIR – Which Delivers Greater Accuracy?

Our system utilizes a network of radio nodes that operate in carefully orchestrated cycles. Key points include:

• Dual-Mode Operation: Radio nodes can function as transmitters, receivers, or transceivers. During a measurement cycle, selected nodes emit an initial signal while others capture the response. This flexible configuration ensures optimal coverage and accuracy.
• Step Sequences: Each measurement cycle is divided into step sequences. In each sequence, the first step involves transmitting an initial signal at a specific carrier frequency, while the subsequent step captures a response signal at a second carrier frequency.
• Coherent Signal Exchange: All transmitted signals within a cycle maintain phase coherence. This coherence is critical to accurately extracting information about propagation delays and the impact of indirect paths.

Our approach leverages cutting-edge signal processing techniques:

• Frequency Domain Analysis: By sweeping the carrier frequency across a predetermined domain—or employing frequency hopping—we sample the channel’s response at multiple points. This method provides a high-resolution picture of the channel’s behavior.
• Channel Transfer Functions: The collected data is processed to derive channel transfer functions. These functions describe the transmission properties between radio nodes, accounting for both direct and indirect (multipath) propagation.
• Time and Frequency Offset Determination: Our algorithms accurately compute the time offsets and frequency offsets between nodes, enabling precise distance measurements and synchronization.
• Transformation to Time Domain: In addition to frequency domain analysis, we transform the data into the time domain. This process yields channel impulse responses that reveal the individual propagation paths, making it possible to distinguish between direct signals and those affected by reflections or environmental interference.

Beyond positioning, our technology enables a detailed understanding of the surrounding radio environment:

• Interference Analysis: The system captures and analyzes interference signal components. By comparing these with known reference profiles, we can determine whether a radio node is genuinely part of a given environment.
• Dynamic Environment Mapping: The methods extract features that represent the spatial and temporal characteristics of the environment. These features can be used to identify changes—such as the movement of objects or the presence of additional interference—that affect system performance.
• Security Enhancements: The integrated analysis of channel characteristics and interference profiles supports robust integrity checks. This ensures that only authorized devices, correctly situated within the expected environment, are granted access.

Our technology is designed for seamless integration:

• Data Fusion: Our systems support sensor fusion by integrating radio measurement data with additional sensor inputs (e.g., inertial sensors). This enhances the accuracy of positioning and motion tracking.
• Scalable Architecture: The multi-node design allows for the expansion of the system to cover larger areas or more complex environments. Whether deployed in industrial facilities, smart buildings, or secure access systems, our solution scales to meet the needs of any application.
• Robust and Cost-Effective: By utilizing efficient measurement cycles and advanced signal processing algorithms, we deliver high performance while keeping complexity and cost low.

Explore the details in this section to see how our innovative approach turns complex radio frequency data into precise, actionable insights.