Time-Domain Alamouti Encoding for 5G Antenna Diversity

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Solution Overview

Problem

Existing wireless communication systems, particularly in 5G technology, face challenges in achieving continuous index and phase in uplink antenna diversity schemes, which limits their ability to provide tone-wise Alamouti in the frequency domain.

Innovation Solution

The implementation of time-domain sample-wise Alamouti encoding, where the second signal is encoded with a continuous index and continuous phase, and symbols are flipped and conjugated, allowing for tone-wise Alamouti in the frequency domain by phase rotating every other symbol by 180 degrees.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a known uplink antenna diversity scheme is used, then antenna diversity is provided, but the index and phase become discontinuous, preventing tone-wise Alamouti in the frequency domain

Engineering Contradiction:

Improveantenna diversityVSAvoidcontinuity of index and phase

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent applies parameter changes by modifying the encoding parameters of the second signal. Specifically, it changes the phase rotation parameter (rotating every other symbol by 180 degrees) and the indexing parameter (using continuous indexing) to achieve both antenna diversity and continuous index/phase properties simultaneously.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent inverts the conventional approach by applying Alamouti encoding in the time domain rather than the frequency domain. This inversion allows the system to achieve tone-wise Alamouti properties in the frequency domain as a result, while maintaining continuous index and phase continuity that would be difficult to achieve with traditional frequency-domain approaches.

Inventive Principle:

Principle #13The other way round (Inversion)

2Reliability

If time-domain sample-wise Alamouti encoding is implemented with continuous index and phase, then tone-wise Alamouti is achieved in the frequency domain, but the encoding complexity increases

Engineering Contradiction:

Improvetone-wise AlamoutiVSAvoidencoding complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent substitutes complex frequency-domain processing with simpler time-domain operations. By performing Alamouti encoding in the time domain through simple operations like symbol flipping, conjugation, and phase rotation, the system avoids the computational complexity of frequency-domain implementations while achieving the same diversity benefits.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Stability of the object's composition

If symbols are flipped and conjugated with phase rotation, then continuous phase is achieved, but the processing steps increase

Engineering Contradiction:

Improvecontinuous phaseVSAvoidprocessing steps

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-defining the phase rotation pattern (180 degrees for every other symbol) and continuous indexing scheme before transmission. These preliminary configurations ensure continuous phase without requiring complex real-time adjustments, simplifying the overall processing while maintaining phase continuity.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS10211953B2Antenna diversity schemes

Publication Date: 2019.02.19 QUALCOMM INC

AI summary

Certain aspects of the present disclosure relate to methods and apparatus for implementing one or more antenna diversity schemes using communications systems operating according to 5G technologies. For example, techniques and apparatus may be provided for employing Alamouti encoding in a time domain for one or more portions of a plurality of modulated symbols associated with a first signal to be transmitted by a first antenna or a second signal to be transmitted by a second antenna to create a first plurality of encoded symbols or a second plurality of encoded symbols with tone-wise Alamouti in the frequency domain.