Spatial Whitening and Adaptive Beamforming for Wireless Signal Detection

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Solution Overview

Problem

Wireless networks face challenges in unlicensed and crowded licensed bands due to interference, which hinders network discovery and synchronization processes, especially for remote nodes in wireless communication systems.

Innovation Solution

The implementation of spatial array diversity techniques, including spatial whitening and adaptive beamforming, to mitigate interference and enhance signal detection during network discovery and synchronization, utilizing spatial whitening to equalize signal power and adaptive beamformers to reduce interference and improve detection sensitivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If spatial array diversity techniques are implemented to mitigate interference, then signal detection reliability is improved, but device complexity increases

Engineering Contradiction:

Improvesignal detection reliabilityVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the interference mitigation process into distinct stages: spatial whitening as a pre-processing step followed by adaptive beamforming. This segmentation allows each component to be optimized independently, reducing overall system complexity while maintaining reliability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Spatial whitening is applied as a preliminary action before adaptive beamforming to pre-whiten the received signals and equalize power spectral density. This preliminary processing simplifies subsequent beamforming operations by removing correlations and normalizing power levels across frequency bins.

Inventive Principle:

Principle #10Preliminary action

2Measurement precision

If adaptive beamforming is used to reduce interference, then measurement precision is improved, but computational requirements increase

Engineering Contradiction:

Improvesignal parameter estimation precisionVSAvoidcomputational energy consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The adaptive beamformer uses the received signals themselves to compute the spatial covariance matrix and derive beamforming weights without requiring external training sequences or additional reference signals. This self-service approach reduces computational overhead while maintaining estimation precision.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent transforms the beamforming weight calculation into the frequency domain using FFT operations, changing the computational parameter from time-domain convolution to frequency-domain multiplication. This parameter change significantly reduces computational complexity while preserving measurement precision.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If spatial whitening is applied to equalize signal power, then detection sensitivity is improved, but processing time increases

Engineering Contradiction:

Improvedetection sensitivityVSAvoidprocessing time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces complex time-domain spatial whitening operations with frequency-domain processing using FFT-based methods. This substitution maintains detection sensitivity by preserving the spectral characteristics of signals while dramatically reducing processing time through efficient frequency-domain algorithms.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS12040921B1Systems and methods for calculating beamforming weights used in wireless network discovery, synchronization, and reference signal waveform identification

Publication Date: 2024.07.16 TARANA WIRELESS

AI summary

Physical layer processing methods for network acquisition by remote nodes in wireless communication systems are described herein. New methods for wireless network discovery and synchronization by remote nodes are described herein that utilize spatial (e.g., antenna array) processing algorithms which may achieve enhanced functioning in challenging radio frequency environments, such as those containing interference and multipath distortion effects. These methods may include advantageous use of spatial whiteners and associated pluralities of adaptive beamformers to detect network reference and synchronization signals and estimate their parameters.