Control Channel Element Index Adaptation for LTE Coverage

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Solution Overview

Problem

Current LTE systems face challenges in maintaining consistent radio coverage for control channel transmissions due to varying available control channel resources across subframes, which hinders the effectiveness of repeated control channel messages.

Innovation Solution

The method involves skipping or refraining from transmitting control channel information in subframes where the start control channel element index exceeds the available control channel elements, ensuring that only valid control channel candidates are repeated across subframes, thereby maintaining consistent transmission and reception.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If control channel information is repeated across all subframes, then transmission coverage is extended, but resource consistency and decoding reliability deteriorate when available control channel elements vary across subframes

Engineering Contradiction:

Improvedecoding reliabilityVSAvoidtransmission efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent applies dynamics by making the control channel transmission adaptive to varying resource conditions across subframes. The transmitting node determines whether to transmit control channel information in each subframe based on comparing the start CCE index against the number of available CCEs in that subframe. This dynamic adaptation ensures that transmissions only occur when resources are sufficient, maintaining decoding reliability while avoiding wasted transmissions in resource-constrained subframes.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the transmission parameter (whether to transmit control channel information) based on the available resource parameter (number of CCEs) in each subframe. By comparing the start CCE index with the available CCE count and adjusting the transmission decision accordingly, the system adapts to varying resource conditions, ensuring consistent decoding reliability across subframes with different resource availability.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If control channel transmissions are performed in subframes with insufficient resources, then transmission opportunities are maximized, but resource allocation consistency and message validity deteriorate

Engineering Contradiction:

Improvetransmission opportunitiesVSAvoidresource allocation consistency

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary action by pre-determining the set of control channel candidates based on the available CCEs in each subframe before actual transmission. The transmitting node compares the start CCE index with the number of available CCEs in advance, and only proceeds with transmission when resources are sufficient. This preliminary check ensures that all transmitted control channel messages are valid and consistently resource-allocated, preventing transmissions in subframes with insufficient resources.

Inventive Principle:

Principle #10Preliminary action

3Productivity

If control channel information is transmitted without checking resource availability, then transmission frequency is increased, but interference and decoding errors increase

Engineering Contradiction:

Improvetransmission frequencyVSAvoidinterference and decoding errors

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies feedback by using the available CCE information (resource status feedback) to control transmission decisions. The transmitting node receives feedback about the number of available CCEs in each subframe and uses this feedback to determine whether to transmit control channel information. This feedback mechanism ensures that transmissions only occur when resources are sufficient, reducing interference and decoding errors while maintaining appropriate transmission frequency.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS10172117B2Transmitting and receiving nodes and methods therein for control channel transmissions in a radio communications network

Publication Date: 2019.01.01 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

Embodiments herein relate to a transmitting node and method therein for transmitting channel information in subframes to a receiving node. Each subframe comprises a number of control channel elements and a set of control channel candidates. The transmitting node transmits control channel information in a subframe when a start control channel element index of a control channel candidate is smaller than or equal to the number of available control channel elements in a predefined subframe, and refrains from transmitting control channel information when the start control channel element index of the control channel candidate is larger than the number of available control channel elements in the predefined subframe. The embodiments also relate to a receiving node and method therein.