Joint Encoding Dual-Carrier ACK/NACK Signaling

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Solution Overview

Problem

Existing proposals for supporting dual-carrier HSDPA operations in wireless communication systems face issues such as severe coverage impact and codebook deficiencies, including low minimum Hamming distance and inability to support PRE and POST operations effectively.

Innovation Solution

Development of enhanced multiple carrier codebooks with improved minimum Hamming distance and inclusion of PRE and POST operations, ensuring clear acknowledgment signaling across multiple carriers and avoiding ambiguity between single and multiple carrier modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If two separate HS-DPCCHs are used for ACK/NACK signaling on dual carriers, then each carrier can be acknowledged independently, but coverage is severely impacted when both HS-DPCCHs are transmitted

Engineering Contradiction:

ImproveACK/NACK signaling reliabilityVSAvoidcoverage impact

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent combines ACK/NACK signaling for two carriers into a single HS-DPCCH channel using joint encoding. This merging approach allows both carriers to be acknowledged simultaneously without requiring separate physical channels, thereby eliminating the coverage impact that occurs when multiple HS-DPCCHs are transmitted concurrently.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single HS-DPCCH channel is designed to carry multiple ACK/NACK indications through joint encoding, making it a multi-functional channel that can signal acknowledgment status for both carrier 1 and carrier 2. This universal approach allows one channel to perform the work of multiple specialized channels.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Object-affected harmful factors

If joint encoding of two ACK/NACK indications is used, then coverage is improved, but the codebook has low minimum Hamming distance which degrades error rate performance

Engineering Contradiction:

Improvecoverage impactVSAvoidmessage error rate performance

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent changes the codebook parameters by constructing a new codebook with 16 code words of length 10, achieving a minimum Hamming distance of 4. This parameter optimization improves the error rate performance while maintaining the single-channel joint encoding approach for dual-carrier ACK/NACK signaling.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If existing MIMO code words are reused for dual carrier signaling, then implementation is simplified, but PRE and POST operations cannot be supported and codebook ambiguity arises

Engineering Contradiction:

Improveimplementation complexityVSAvoidsupport for PRE/POST operations

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent segments the codebook into distinct functional groups: 8 code words for ACK/NACK signaling and 8 code words for PRE/POST operations. This segmentation allows the codebook to clearly distinguish between different operational modes, eliminating ambiguity and supporting both dual-carrier signaling and PRE/POST functions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of trying to fit PRE/POST operations into existing MIMO code words, the patent inverts the approach by creating a dedicated set of code words specifically for PRE/POST operations. This inversion resolves the conflict between using existing code words and supporting new operational modes.

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentEP3487099B1Multiple carrier acknowledgment signaling

Publication Date: 2019.12.18 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

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AI summary

There is provided a method in a remote terminal for acknowledgment uplink signaling in a multiple-carrier mode. The method comprises determining a code word that jointly encodes acknowledgment signaling for at least two carriers from a multiple carrier codebook that includes at least eight code words that are defined to have a single carrier codebook as a sub-codebook of the multiple carrier codebook. The method further comprises transmitting from the remote terminal to a wireless network node an uplink signaling message that includes the determined code word. The multiple carrier code book includes a set of values for each of code pairs ACK/DTX, NACK/DTX, DTX/ACK, DTX/NACK, NACK/ACK, ACK/NACK, ACK/ACK, and NACK/NACK, achieving a minimum Hamming distance of 4 between each of the code word pairs and achieving a Hamming distance of 10 between code pairs DTX/ACK and DTX/NACK, between code pairs ACK/DTX and NACK/DTX, between code pairs ACK/NACK and NACK/ACK, and between code pairs ACK/ACK and NACK/NACK.