Subband Precoding for Higher Channel Capacity With Lower Signaling

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Solution Overview

Problem

Existing radio communication technologies, such as 3GPP LTE and 5G NR, lack efficient methods for utilizing the channel capacity of precoded radio channels and result in excessive signaling overhead due to wideband precoding across the entire bandwidth.

Innovation Solution

Implementing subband precoding by applying different precoders for each subband of a radio channel, allowing for more efficient use of channel capacity and reduced signaling overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If wideband precoding is applied across the entire bandwidth, then the radio device can perform beamformed transmission, but the signaling overhead increases

Engineering Contradiction:

Improvebeamformed transmission capabilityVSAvoidsignaling overhead

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The patent divides the wideband precoding into multiple subband precoders, where each subband has its own precoding matrix. This segmentation allows the system to maintain beamforming capability while reducing the signaling overhead by only indicating the precoder for each subband rather than the entire bandwidth, thus resolving the contradiction between reliability and information loss.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different precoding matrices to different subbands based on local channel conditions. Each subband can have optimized precoding parameters tailored to its specific characteristics, which improves the overall system reliability while the localized nature of the optimization reduces the total signaling overhead compared to wideband precoding.

Inventive Principle:

Principle #3Local quality

2Productivity

If a single precoder is applied over the entire bandwidth, then the device complexity is reduced, but the channel capacity utilization becomes inefficient

Engineering Contradiction:

Improvechannel capacity utilizationVSAvoidprecoder management complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the bandwidth into multiple subbands, each with its own precoder. This allows the system to better utilize channel capacity by adapting to frequency-selective fading in different subbands, while the complexity is managed through efficient signaling mechanisms that indicate precoders for each subband without requiring full precoder matrices to be transmitted.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies precoding at the subband level rather than uniformly across the entire bandwidth. This partial action approach allows the system to focus computational and signaling resources on the most critical subbands, improving channel capacity utilization while keeping device complexity manageable through selective precoding application.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS12483303B2Subband precoding technique

Publication Date: 2025.11.25 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

A technique for transmitting data on at least two subbands (602) of a radio channel (600). As to a method aspect of the technique performed by a radio device, control information indicative of at least two precoders for the at least two subbands (602) of the radio channel (600) is received. The data is transmitted on the at least two subbands (602) using the at least two precoders.