Beamformer-Triggered Sounding for Low-Overhead CSI Estimation
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Solution Overview
Problem
Existing wireless communication networks face inefficiencies in coordinating communication services to a larger number of devices while minimizing transmission and processing overhead from traditional sounding protocols, particularly in multi-path channel environments.
Innovation Solution
A solicited sounding framework initiated by the beamformer, which transmits a sounding trigger to beamformees to solicit dedicated training signals, reducing the need for extensive processing and bandwidth consumption by beamformees, and allowing coordinated CSI estimation for improved communication efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional explicit sounding protocols are used to characterize multipath communication channels, then channel state information can be obtained for beamforming, but transmission overhead and processing overhead increase significantly
Solution Approach 1:
Instead of the beamformer transmitting sounding signals and receiving detailed feedback from beamformees (traditional explicit sounding), the beamformer transmits a compact sounding trigger and derives channel state information by processing the beamformee's uplink training signals. This inverts the traditional feedback direction and reduces processing burden on beamformees while maintaining CSI accuracy through reciprocal channel estimation.
Solution Approach 2:
The patent extracts only the essential triggering function from traditional explicit sounding protocols, separating the complex feedback generation and transmission processes. The beamformer extracts channel state information from uplink training signals without requiring beamformees to perform complex processing, thereby reducing processing overhead while maintaining measurement precision.
2Measurement precision
If traditional explicit sounding protocols are used to support multiple stations, then channel characterization is achieved, but transmission overhead increases
Solution Approach 1:
The patent merges the sounding trigger transmission with regular downlink data transmissions, and combines multiple beamformees' training signals into a single uplink transmission opportunity. This consolidation reduces the number of separate signaling exchanges required, thereby reducing transmission overhead while maintaining accurate channel characterization for multiple stations.
Solution Approach 2:
The sounding trigger serves multiple functions simultaneously: it initiates the sounding process, allocates uplink training resources, and provides timing synchronization. The uplink training signals serve dual purposes as both channel estimation references and data transmissions. This multi-functionality reduces the total transmission overhead required for sounding operations.
Data Source
AI summary
Example implementations are directed to methods and systems employing a solicited sounding protocol that includes an efficient communication sequence for operating a wireless transceiver transmitting a sounding trigger to one or more beamformees via a forward channel, receiving at least one dedicated training signal from the one or more beamformees via a reverse channel in response to the sounding trigger, and for each of the received dedicated training signal. The method also includes estimating forward CSI derived based on the dedicated training signal from an associated beamformee; and where subsequent packets are precoded with precoding derived from the forward CSI for transmission to the associated beamformee via the forward channel. Example aspects including scheduling multiple dedicated training signals from one or more beamformees based on a single sounding trigger.