EPDCCH PRB Pair Indication via Logical Bitmaps

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Solution Overview

Problem

Current methods for indicating which physical resource block (PRB) pairs a user equipment (UE) should monitor for the Enhanced Physical Downlink Control Channel (EPDCCH) in LTE-Advanced networks are inefficient, requiring excessive signaling overhead and not utilizing knowledge of unavailable PRB pairs.

Innovation Solution

The method involves sending logical bitmaps and location indicators from the base station to the UE, which are mapped to PRB pairs, excluding unavailable ones, to reduce signaling overhead and allow flexible EPDCCH monitoring, with options for multiple sets and patterns of PRB pairs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If traditional bitmap methods are used to indicate all PRB pairs, then complete monitoring information is provided, but signaling overhead increases excessively

Engineering Contradiction:

Improvemonitoring information completenessVSAvoidsignaling overhead

Core Design Contradiction:

Loss of informationVSQuantity of substance

Solution Approach 1:

The patent extracts and excludes PRB pairs that are known to be unavailable for EPDCCH transmission from the bitmap representation. By removing these unnecessary entries, the signaling overhead is reduced while still providing complete monitoring information for actually available PRB pairs.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the PRB pair indication into multiple components: unavailable PRB pair indicators, available PRB pair indicators, and set assignment information. This segmentation allows efficient representation by only encoding necessary information rather than providing a complete bitmap of all PRB pairs.

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If multiple sets of PRB pairs are supported, then flexibility in EPDCCH monitoring is improved, but the product of total PRB pairs and total sets increases signaling requirements

Engineering Contradiction:

ImproveEPDCCH monitoring flexibilityVSAvoidsignaling bits required

Core Design Contradiction:

Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent implements dynamic set assignment where PRB pairs can be flexibly assigned to different EPDCCH sets based on availability and configuration. The system can adaptively manage multiple sets with varying numbers of PRB pairs, allowing flexible monitoring configurations without requiring static allocation for all possible combinations.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent applies local quality by providing detailed monitoring information only for specific PRB pairs within specific sets, rather than uniform representation for all PRB pairs across all sets. Each set receives customized indication based on its actual composition and availability, reducing overall signaling requirements.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS9031021B2Method and apparatus for indicating physical resource block pairs for EPDCCH

Publication Date: 2015.05.12 ALCATEL LUCENT SA

AI summary

A method of specifying one or more sets of one or more physical resource block (PRB) pairs from among a plurality of PRB pairs in a subframe that a user equipment (UE) is to monitor for an enhanced physical downlink control channel (EPDCCH) includes sending, from a base station, a first representation of the PRB blocks, the representation including a plurality of bits, a total number of the plurality of bits being less than a product of total number of the plurality of PRB pairs and a total number of the one or more sets, the first representation indicating which of the plurality of PRB pairs are in at least one of the one or more sets of one or more PRB pairs the UE is to monitor for the EPDCCH.