How to Build a High-Precision UWB Indoor Positioning System Based on DW3000

I. Define Requirements and Select the Ranging Method

To achieve centimeter-level indoor positioning, system requirements must be clearly defined at the outset, including target accuracy, update rate, latency, battery life, coverage area size, and spatial geometry. Based on these constraints, an appropriate ranging method should be selected and success criteria established for subsequent validation.

In UWB positioning, Two-Way Ranging (TWR) is an asynchronous method that offers relatively simple deployment. Considering deployment complexity and system scale, this article adopts a TWR-based UWB ranging solution. From an engineering practice perspective, it systematically introduces how to build an indoor positioning system based on the DW3000 platform.

II. Materials and Toolchain Preparation

1. Bill of Materials

Anchor nodes and tag nodes

DW3000 development modules are selected, based on Qorvo’s DW3000 chip. The chip is reported to comply with the IEEE 802.15.4z HRP standard and supports the physical-layer and ranging features required by certification frameworks.

For anchor nodes, the DW3000 module can be combined with a Qorvo DWM3000EVB evaluation board and an STM32 Nucleo board, along with onboard or external antennas.

Tag nodes can also use DW3000 development modules, equipped with compact FPC antennas and wearable or handheld enclosures, powered by portable rechargeable batteries.

2. Toolchains and Libraries

Compiler and SDK For DW3000 development modules, vendor-provided drivers and example code are used. These target the DW3000 series and the IEEE 802.15.4z HRP ranging standard. Under line-of-sight (LOS) conditions and with proper calibration, the chip manufacturer reports typical ranging accuracy down to approximately 10 cm.

Programming tools Standard programmers are used to flash firmware onto the MCU boards for both anchors and tags.

Serial console Any USB serial terminal capable of reading logs, configurations, and ranging outputs can be used.

Visualization and analysis Python scripts are used to parse logs and generate range histograms and time-series plots. A simple README is retained to allow plots to be regenerated.

Version control Toolchain versions are fixed, with exact SDK tags and compiler versions recorded. Firmware repositories are tagged at each milestone to ensure reproducibility.

III. Module Selection Recommendations

From a system selection perspective, development boards based on the DW3000 chip are better suited for R&D and deep customization scenarios, offering greater debugging flexibility. Developers can leverage official Qorvo drivers and reference implementations to perform low-level feature development and algorithm optimization, making them suitable for projects requiring customized protocols, ranging workflows, or system architectures.

For applications that require rapid deployment and practical implementation—such as small to medium-sized indoor positioning systems or proof-of-concept projects—the UWB650Pro module is recommended.

The UWB650Pro is based on the Qorvo DW3000 chip and highly integrates RF and control circuitry. It supports TWR-based ranging and positioning, as well as RSSI (Received Signal Strength Indicator)–assisted positioning.

Users do not need to develop chip-level drivers. Instead, system configuration (e.g., data rate and positioning parameters) can be completed via a UART interface, enabling fast system setup.TWR provides the foundation for high-precision ranging, while RSSI can serve as auxiliary information (for anchor selection or range result weighting). The combination further improves overall positioning robustness.

To address antenna delay calibration—one of the most common challenges in UWB applications—G-NiceRF has preloaded delay parameters for multiple commonly used UWB antennas in the UWB650 PC configuration software. Users simply select the corresponding antenna model and configure the channel parameters. The system automatically completes calibration, eliminating the need for manual measurement and tuning, and enabling stable and reliable high-precision ranging.

Recommended UWB650 Solution Bill of Materials

IV. Hardware Assembly, Power Planning, and Enclosure Selection

Hardware Assembly Considerations

Wiring and interfaces

Mount the UWB module and controller on a rigid structure and keep the ground plane beneath the RF section clean. Use shielded USB or UART cables and add strain relief for connectors subject to movement. Avoid placing metal near antenna edges, as this may alter antenna characteristics and degrade signal quality and positioning accuracy.

Power budget and battery selection

Plan power consumption based on radio operating states. Reception typically consumes more power than transmission. Reduce power usage by shortening receive windows and airtime, using the highest data rate that meets range requirements, and minimizing preamble and payload length. Estimate battery life using average current and duty cycle across operating modes, and re-evaluate after parameter adjustments.

Enclosure Selection and Installation

Enclosure requirements

Enclosures should not act as RF filters. Keep antennas unobstructed and maintain consistent orientation. Non-conductive, RF-friendly enclosures are preferred, ideally mounted directly over the antenna area.

Anchor mounting

Secure anchors firmly to rigid structures to avoid vibration. Maintain clear line-of-sight to the coverage area and avoid large metal surfaces unless their impact has been measured and compensated. Label each installed node to facilitate calibration and configuration tracking. Verify compliance with local UWB regulations before deployment.

V. Anchor Placement Planning and Network Calibration

Anchor Placement Guidelines

Geometric considerations

Distribute anchors to provide diverse angles of arrival and avoid collinear or tightly clustered layouts. For 3D positioning, anchors should not be coplanar; elevate at least one anchor to improve geometric diversity.

Height, position, and visibility

Install anchors high on walls or ceilings to reduce obstruction and increase LOS probability. Maintain sufficient clearance around antennas and follow vendor antenna orientation guidelines.

Small and complex spaces

Small rooms benefit from four non-coplanar anchors placed around the perimeter. Medium spaces may start with perimeter anchors and add anchors in blind areas. Complex layouts may require additional anchors to open new signal paths.

Site survey

Walk the site, sketch coverage areas, mark reflectors and obstacles, and perform quick range or RSSI/SNR tests. Record provisional anchor coordinates and ensure power and backhaul availability.

Calibration and Network Debugging

Antenna delay and hardware offset calibration

Set initial antenna delays, collect range data at known distances, and fit linear models. Store transmit/receive delay offsets or slope parameters in non-volatile memory.

Baseline testing

Place tags at marked positions and record dwell times. Validate continuity and drift during slow movement. Save raw measurements, computed ranges, positions, and configuration files.

Checklist

Verify firmware versions and commit hashes, anchor coordinates and heights, radio configurations, applied calibrations, and TWR operation status. Ensure logging is enabled.

FAQ: Common Questions About DW3000 UWB Indoor Positioning

Q1: Can DW3000 truly achieve centimeter-level indoor positioning?

A: Yes. Under good LOS conditions, with proper anchor geometry and antenna delay calibration, TWR-based DW3000 systems can reliably achieve centimeter-level accuracy. Actual performance depends mainly on anchor layout and environmental reflections.

Q2: How important are the number and placement of anchors?

A: Extremely important. Anchors should be well distributed, avoid collinearity or coplanarity, and preferably be installed at elevated positions. Proper geometry often matters more than simply adding anchors.

Q3: Is antenna delay calibration mandatory?

A: Yes. Uncalibrated antenna delays introduce systematic ranging errors and are a major factor affecting accuracy. Module solutions with preloaded antenna parameters significantly reduce calibration effort.

Q4: How should I choose between a development board and the UWB650Pro module?

A: Use DW3000 development boards for low-level algorithm or protocol customization. For fast deployment and engineering implementation, the UWB650Pro module is more suitable and supports rapid system setup via UART.

Q5: How can stability be improved in complex indoor environments?

A: Improve stability by increasing anchor height diversity, optimizing geometric layouts, using RSSI-assisted methods to handle NLOS conditions, and performing thorough on-site calibration.