Unified Wireless Ranging Protocol Reducing Frame Overhead
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing beamforming calibration techniques in wireless communication systems do not include essential channel calibration metrics like Angle of Arrival (AoA), Angle of Departure (AoD), Azimuth, Channel Frequency Response (CFR), Channel Impulse Response (CIR), Power Delay Profile (PDP), and First Arrival Correction (FAC), leading to increased system overhead and latency.
Innovation Solution
The method leverages existing Null Data Packet (NDP) and Null Data Packet Announcement (NDPA) exchanges to transmit angular information and channel calibration parameters, using Compressed Beamforming Feedback (CBF) frames to facilitate symmetric RTT/AoA/AoD/Azimuth exchange between wireless STAs, potentially in a broadcast or multicast fashion, and employs Beam Refinement Protocol (BRP) frames within a unified protocol framework.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional separate protocols are used for channel calibration and positioning, then comprehensive channel metrics can be obtained, but system overhead and latency increase due to multiple frame exchanges
Solution Approach 1:
The patent combines channel calibration and positioning functions into a unified protocol framework where a single NDP/NDPA frame exchange simultaneously provides both channel metrics (AoA, AoD, CFR, CIR, PDP, FAC) and positioning information (RTT, angular data). This merging eliminates the need for separate calibration and positioning procedures, reducing frame exchanges while maintaining comprehensive measurement capabilities.
Solution Approach 2:
The unified protocol makes the NDP/NDPA frame structure universal by enabling it to serve multiple functions: channel sounding, angle estimation, time-of-flight measurement, and beamforming calibration. The same frame exchange that calibrates the channel also provides all necessary data for positioning, making the protocol multi-functional and eliminating redundant communications.
2Measurement precision
If multiple separate frame exchanges are used for calibration and positioning, then accurate measurements can be obtained, but the number of protocol steps and system overhead increase
Solution Approach 1:
The patent merges multiple protocol functions into a single unified exchange sequence. The NDP announcement frame and null data packet are designed to carry both channel calibration data and positioning measurements simultaneously, reducing the number of protocol steps from multiple separate exchanges to a single integrated procedure.
Solution Approach 2:
The unified protocol structure enables a single frame exchange to perform multiple functions: channel sounding for calibration, angle-of-arrival and angle-of-departure estimation, round-trip-time measurement, and beamforming optimization. This multi-functionality reduces protocol complexity while maintaining measurement accuracy.
3Measurement precision
If comprehensive channel metrics are collected through multiple exchanges, then channel characterization is improved, but system overhead increases
Solution Approach 1:
The patent combines channel calibration and positioning measurements into a single unified exchange, where the NDP/NDPA frames carry both channel metrics (CFR, CIR, PDP) and positioning data (AoA, AoD, RTT). This merging reduces the quantity of frames required while maintaining comprehensive channel characterization capabilities.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Disclosed embodiments facilitate wireless channel calibration, including ranging and direction finding, between wirelessly networked devices. In some embodiments. a method on a first station (STA) may comprise: transmitting a first NDPA frame to one or more second stations (STAs), the first NDPA frame comprising a first bit indicating that one or more subsequent frames comprise ranging or angular information; and transmitting, after a Short Interval Frame Space (SIFS) time interval, a second frame. The second frame may be one of: a Null Data Packet az (NDP_az) frame with information about a time of transmission of the NDP_az frame, or a Null Data Packet (NDP) frame, or a Beam Refinement Protocol (BRP) frame. The first NDPA frame may be unicast, multicast, or broadcast.