Soft Buffer Partitioning for Carrier Aggregation

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Solution Overview

Problem

In LTE-A systems with carrier aggregation, the existing methods for handling soft buffers are inefficient, leading to increased blocking probabilities and diminished system throughput when storing multiple HARQ processes, as they either restrict storage to 8 processes or divide the buffer into too many partitions, reducing coding performance and requiring more retransmissions.

Innovation Solution

A method that determines weightings for primary and secondary component carriers to divide the soft buffer into sub-blocks of varying sizes, allowing efficient arrangement of HARQ processes, thereby reducing blocking probabilities and ensuring rapid recovery of control information and data on primary carriers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the soft buffer is divided into too many partitions to store multiple HARQ processes, then the blocking probability increases, but the coding performance deteriorates and more retransmissions are required

Engineering Contradiction:
Improveblocking probabilityVSAvoidsystem throughput
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies local quality by assigning different buffer sizes to different partitions based on the importance of component carriers. The primary component carrier receives a larger buffer allocation while secondary component carriers receive smaller allocations, optimizing the balance between blocking probability and coding performance for each carrier type.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the buffer allocation parameter dynamically based on carrier type. By adjusting the number of soft buffer bits allocated to different partitions according to whether they correspond to primary or secondary component carriers, the system optimizes both blocking probability and coding performance.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If the soft buffer is restricted to store only 8 HARQ processes, then the device complexity is reduced, but the system throughput is diminished when multiple component carriers are configured

Engineering Contradiction:
Improvesoft buffer management complexityVSAvoidsystem throughput
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent segments the soft buffer into multiple partitions, where each partition corresponds to a specific component carrier. This segmentation allows the system to store HARQ processes for multiple component carriers while maintaining manageable complexity through structured organization of the buffer resources.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent creates a multi-functional soft buffer system that can handle HARQ processes for both primary and secondary component carriers simultaneously. The unified buffer management approach with weighted partitions enables the system to serve multiple carriers with different requirements through a single coordinated mechanism.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP2518927B1Method of handling soft buffer for carrier aggregation and related communication device
Publication Date: 2020.05.06 ACER INC
  • EP2518927B1 patent drawingFigure 1
  • EP2518927B1 patent drawingFigure 2
  • EP2518927B1 patent drawingFigure 3

AI summary

A method of handling a soft buffer of a mobile device in a wireless communication system is disclosed. The mobile device is configured a plurality of component carriers, called CCs hereinafter, by a network of the wireless communication system. The plurality of CCs comprise a primary CC, called PCC hereinafter, and at least one secondary CC, called SCC hereinafter. The method comprises determining a plurality of weightings corresponding to the plurality of CCs according to an indication; determining a plurality of sizes of a plurality of sub-blocks according to the plurality of weightings; and dividing the soft buffer into the plurality of sub-blocks according to the plurality of sizes of the plurality of sub-blocks, to arrange a plurality of hybrid automatic repeat request, called HARQ hereinafter, processes of the plurality of CCs in the plurality of sub-blocks.