HARQ Buffer Segmentation for TTI Adaptation

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Solution Overview

Problem

In LTE wireless communication systems, the complexity and cost of User Equipment (UE) increase due to the need to handle varying and shorter Transmission Time Intervals (TTIs) for Hybrid Automatic Repeat Request (HARQ) processes, leading to inefficient use of HARQ buffers and potential latency issues.

Innovation Solution

The method involves determining and allocating HARQ buffer sizes based on the Transmission Time Interval (TTI), allowing efficient handling of HARQ processes and associated buffers, reducing complexity and cost by dividing soft buffers into sub-HARQ buffers for different TTI lengths, and signaling TTI indications to ensure optimal buffer allocation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If HARQ processes with different TTI lengths are handled using a unified buffer allocation method, then the system maintains simplicity in buffer management, but the complexity and cost of the wireless device increases due to inefficient buffer usage and the need to handle varying TTI lengths

Engineering Contradiction:

Improvecomplexity of wireless deviceVSAvoidbuffer allocation efficiency

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

The patent divides the HARQ buffer into separate buffer instances or logical partitions, each dedicated to a specific TTI length. This segmentation allows each buffer to be optimized for its specific TTI length, avoiding the complexity of managing variable-length buffers in a unified structure while improving allocation efficiency for each TTI type.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic buffer allocation where the buffer size and configuration are adapted based on the specific TTI length being used. The system can dynamically select and configure appropriate buffer parameters according to the TTI length, enabling efficient handling of varying TTI lengths without requiring a complex unified buffer management structure.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If the HARQ buffer size is increased to accommodate varying TTI lengths, then the system can handle different TTI lengths, but the cost of the wireless device increases due to larger buffer requirements

Engineering Contradiction:

Improveability to handle varying TTI lengthsVSAvoidbuffer memory size

Core Design Contradiction:

Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

Instead of allocating one large buffer to handle all TTI lengths, the patent segments the buffer into multiple smaller, dedicated instances for different TTI lengths. This approach provides the adaptability to handle various TTI lengths while keeping the total memory requirement lower than a single oversized buffer would require.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by configuring buffer parameters specifically optimized for each TTI length. Each buffer instance or logical partition has characteristics tailored to its specific TTI length, allowing efficient use of memory for each case rather than provisioning for the worst-case scenario across all TTI lengths.

Inventive Principle:

Principle #3Local quality

3Loss of time

If a unified HARQ buffer is used for all TTI lengths, then the buffer management is simple, but latency increases due to inefficient buffer allocation and switching between different TTI lengths

Engineering Contradiction:

Improvelatency in HARQ processesVSAvoidcomplexity of buffer management

Core Design Contradiction:

Loss of timeVSDevice complexity

Solution Approach 1:

The patent segments the HARQ buffer into dedicated instances for different TTI lengths, which eliminates the need for complex buffer switching and allocation operations when handling different TTI lengths. This segmentation reduces latency by allowing direct access to the appropriate buffer without management overhead, while the complexity is managed through the structured segmentation approach.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary configuration of buffer parameters based on the detected TTI length before actual data processing. By pre-configuring the appropriate buffer instance and its parameters in advance, the system avoids latency-causing operations during active data transmission, while the complexity is managed through automated detection and configuration selection.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS10791552B2Methods and apparatuses for handling of soft buffers

Publication Date: 2020.09.29 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

There is disclosed a method for adapting HARQ buffers in a wireless device (90), said device is adapted for HARQ communication, the method comprising determining (10) a size of a HARQ buffer, the HARQ buffer size being based on a TTI. There is also disclosed a wireless device (90) adapted for HARQ communication, the wireless device comprising a processing circuitry and a memory, said memory containing instructions executable by said processing circuitry, whereby said wireless device is operative to determine a size of a HARQ buffer, the HARQ buffer size being based on a TTI.