Beam-Sweeping Broadcast Decoding with Cross-Beam LLR Combining

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Solution Overview

Problem

Current wireless communication systems, particularly in 5G NR, face challenges in reliably decoding broadcast information that is jointly coded with beam index information, leading to potential errors and reduced reliability in receiving devices.

Innovation Solution

The proposed solution involves coding broadcast information together with beam/symbol index information and transmitting it through beam sweeping, allowing for soft-combining of log-likelihood ratios (LLRs) across adjacent beams to enhance decoding reliability, even when beam indices differ.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If broadcast information is transmitted through beam sweeping with jointly coded beam index, then additional useful information can be communicated, but decoding reliability deteriorates due to inability to soft-combine LLRs across beams with different indices

Engineering Contradiction:
Improveinformation transmission capabilityVSAvoiddecoding reliability
Core Design Contradiction:
Loss of informationVSReliability

Solution Approach 1:

The patent segments the beam index information and broadcast information into separate coding fields within the joint codebook. The beam index occupies most significant bits while broadcast information occupies less significant bits, allowing the receiver to separately process and soft-combine LLRs for broadcast information across multiple beams while preserving beam identification capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary processing stage at the receiver that extracts broadcast information from jointly coded beams before performing soft-combining of LLRs. This intermediary step allows the system to benefit from both beam sweeping (for spatial diversity) and reliable decoding (through LLR combining), resolving the contradiction between information transmission and decoding reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If beam index and broadcast information are jointly coded, then communication efficiency improves, but decoding complexity increases due to hypotheses testing requirements

Engineering Contradiction:
Improvecommunication efficiencyVSAvoiddecoding complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent performs preliminary extraction of broadcast information from the jointly coded beam structure before proceeding to LLR soft-combining and final decoding. By preparing the data in advance by separating broadcast information from beam index information, the system reduces the complexity of subsequent decoding operations while maintaining communication efficiency.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies different processing qualities to different parts of the jointly coded information. Beam index information receives full hypothesis testing and decoding attention, while broadcast information receives simplified processing through LLR soft-combining across beams. This local quality differentiation reduces overall decoding complexity while maintaining communication efficiency.

Inventive Principle:
Principle #3Local quality

3Reliability

If LLR soft-combining is performed across beams with different indices, then decoding reliability improves, but system complexity increases due to hypothesis testing of XOR relationships

Engineering Contradiction:
Improvedecoding reliabilityVSAvoidprocessing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the parameter representation by using XOR relationships between adjacent beam indices to identify which beams contain complementary broadcast information. This parameter transformation allows the receiver to perform hypothesis testing on a smaller set of possible beam pairs rather than all possible beam combinations, reducing processing complexity while maintaining decoding reliability through LLR soft-combining.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3571793B1A beam-combining scheme with broadcast beam-sweeping and beam-index indication
Publication Date: 2020.12.02 QUALCOMM INC
  • EP3571793B1 patent drawingFigure 1
  • EP3571793B1 patent drawingFigure 2A~2D
  • EP3571793B1 patent drawingFigure 3

AI summary

Various features related to decoding jointly coded broadcast information and beam/symbol index information to achieve higher reliability and reduced decoding errors from the perspective of a receiving device such as a UE are described. In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be configured to receive a first beam and a second beam of a plurality of beams from a base station, the first beam including broadcast information and a first beam index information j ointly encoded together, and the second beam including broadcast information and a second beam index information jointly encoded together, determine a first LLR of the first beam, determine a second LLR of the second beam, and decode the broadcast information and the first beam index information in the first beam based on both the first LLR and the second LLR.