Iterative Multi-Beam Selection for mmWave Uplink-Downlink Training

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Solution Overview

Problem

Current wireless communication systems face challenges in achieving high reliability and low latency for beamforming operations, especially in millimeter wave (mmW) communications, due to pathloss and blockages, which affect data rates and spectral efficiency.

Innovation Solution

The described techniques involve configuring communication devices with a codebook to perform iterative multi-beam selection using uplink-downlink beam training, where reference signals are transmitted with various combinations of analog beamforming parameters over cycles, allowing for the selection of optimal beamforming parameters based on channel quality reports, thereby improving beamforming reliability and data rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If beamforming operations are performed to mitigate pathloss and blockages, then communication reliability is improved, but system complexity and latency increase

Engineering Contradiction:

Improvebeamforming reliabilityVSAvoidbeam training complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The beam training process is divided into multiple cycles, with each cycle focusing on specific beam combinations. The codebook is segmented into different beamforming parameter sets that are evaluated iteratively, allowing the system to manage complexity by processing beam training in manageable segments rather than all at once.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Reference signals are transmitted with various combinations of analog beamforming parameters before actual data transmission begins. This preliminary beam training phase allows the system to pre-determine optimal beamforming parameters, reducing latency during actual communication while maintaining high reliability.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If iterative beam selection is performed to improve data rates, then spectral efficiency is improved, but time consumption and latency increase

Engineering Contradiction:

Improvedata rateVSAvoidbeam training time

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The beam training process operates continuously over multiple cycles with reference signals being transmitted and evaluated in an ongoing manner. This continuous iterative process allows the system to progressively refine beamforming parameter selections, achieving high data rates without excessive time delays by maintaining constant training activity.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

Beam training is structured as periodic cycles where reference signals are transmitted, channel quality is measured, and beamforming parameters are updated at regular intervals. This periodic structure balances the need for accurate beam selection with time constraints, allowing the system to achieve high spectral efficiency while managing latency through rhythmic training cycles.

Inventive Principle:

Principle #19Periodic action

3Reliability

If multiple combinations of beamforming parameters are tested, then beamforming reliability is improved, but energy consumption increases

Engineering Contradiction:

Improvebeamforming reliabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

Instead of exhaustively testing all possible beamforming parameter combinations, the system evaluates a selected subset of combinations that are most likely to provide optimal performance. This partial action approach achieves sufficient beamforming reliability for mmW communications while significantly reducing the energy consumption associated with testing every possible parameter set.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS11251849B2Iterative multi-beam selection with uplink-downlink beam training

Publication Date: 2022.02.15 QUALCOMM INC

AI summary

Methods, systems, and devices for wireless communications are described. A first device may transmit, to a second device, reference signals using combinations of analog beamforming parameters over multiple cycles. The reference signals may be transmitted for different combinations of transmit beamforming parameters and receive beamforming parameters over different cycles of the multiple cycles. The first device may receive, from the second device over the multiple cycles, a set of reports. Each report may indicate combinations of analog beamforming parameters selected for the analog beamforming parameters at the second device. Each combination of analog beamforming parameters may correspond to different cycles of the multiple cycles. The first device may set, for each radio frequency (RF) chain of a plurality of RF chains associated with the first device, a corresponding combination of analog beamforming parameters, and communicate with the second device via two or more beams based on the setting.