Beamforming Feedback Using Polar Coordinates to Reduce Overhead

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Solution Overview

Problem

Current wireless communication systems require substantial feedback information for beamforming, which is cumbersome and inefficient, especially when using Cartesian coordinates for channel properties, leading to increased data size and complexity.

Innovation Solution

The use of polar coordinates for the beamforming unitary matrix reduces the feedback information needed, allowing for a more efficient and simplified method to convey channel properties, thereby minimizing the data required for beamforming processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If Cartesian coordinates are used to represent channel properties for beamforming, then the representation is straightforward and familiar, but the feedback information size becomes large and the system complexity increases

Engineering Contradiction:

Improveease of representing channel propertiesVSAvoidfeedback information size

Core Design Contradiction:

Ease of operationVSQuantity of substance

Solution Approach 1:

The patent transforms the coordinate system from Cartesian to polar coordinates for representing beamforming feedback information. This parameter change in the mathematical representation reduces the number of bits required to encode the feedback data while maintaining the same level of accuracy in representing channel properties.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If full feedback information is transmitted for accurate beamforming, then the beamforming accuracy is maintained, but the overhead and computational complexity increase

Engineering Contradiction:

Improvebeamforming accuracyVSAvoidsystem complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential components of beamforming feedback information by representing the unitary matrix using polar coordinates. This extraction approach identifies and transmits only the critical parameters needed for accurate beamforming reconstruction, eliminating redundant information and reducing overall system complexity.

Inventive Principle:

Principle #2Taking out (Extraction)

3Measurement precision

If more bits are used to represent beamforming angles, then the resolution and accuracy improve, but the feedback overhead increases

Engineering Contradiction:

Improveangle resolutionVSAvoidfeedback data amount

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent transitions from a two-dimensional Cartesian coordinate system to a polar coordinate system, fundamentally changing the dimensional representation of the feedback parameters. This dimensional transformation allows for more efficient packing of information, achieving high angular resolution with fewer bits by exploiting the natural periodicity and structure of phase and angle parameters in the polar domain.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS7738584B2Beamforming in a wireless communication with a partial estimation to reduce overhead

Publication Date: 2010.06.15 BELL NORTHERN RESEARCH LLC

AI summary

A method for beamforming in a wireless communication begins by receiving a baseband signal. The method continues by receiving a feedback signal that includes a subset of angles, wherein a set of angles provide polar coordinates for a unitary matrix and wherein the subset of angles is a subset of the set of angles. The method continues by determining at least one remaining angle of the set of angles based on the subset of angles. The method continues by determining the polar coordinates for the unitary matrix. The method continues by digitally beamforming the baseband signal using the unitary matrix.