Reference Signal Resource Determination in LTE Systems

Solution Overview

Problem

In LTE systems, excessive reference signal overhead reduces transmission efficiency due to the need for multiple types of downlink reference signals to coexist in the same physical resource block, leading to inefficient use of system resources.

Innovation Solution

A method and apparatus for determining a resource for a reference signal, where R channel resource units are selected from N channel resource units, allowing reference signals to be sent or received in part of the channel resource units used by a physical channel, thereby reducing overhead by optimizing the mapping of reference signals across frequency and time domains.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple types of downlink reference signals (CRS and DMRS) are transmitted in the same physical resource block, then reference signal coverage and reliability are improved, but reference signal overhead increases and transmission efficiency deteriorates

Engineering Contradiction:

Improvereference signal reliabilityVSAvoidreference signal overhead

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies partial action by transmitting reference signals in only some channel resource units rather than all N channel resource units. Specifically, R channel resource units are selected from N channel resource units (where 0 ≤ R < N) to carry reference signals, meaning reference signals are transmitted partially across the available resources rather than universally, thereby reducing overhead while maintaining necessary coverage

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The patent implements local quality by making the reference signal transmission pattern variable across different frequency domain positions. Each frequency domain position f can have a different number of channel resource units allocated for reference signals (R(f)), allowing the system to optimize reference signal density locally based on channel conditions and requirements at each frequency position rather than using a uniform pattern throughout

Inventive Principle:

Principle #3Local quality

2Reliability

If reference signals are transmitted in all channel resource units, then reference signal coverage is maximized, but system resource utilization efficiency decreases

Engineering Contradiction:

Improvereference signal coverageVSAvoidsystem resource utilization efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent applies partial action by transmitting reference signals in only some channel resource units rather than all N channel resource units. Specifically, R channel resource units are selected from N channel resource units (where 0 ≤ R < N) to carry reference signals, meaning reference signals are transmitted partially across the available resources rather than universally, thereby reducing overhead while maintaining necessary coverage

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The patent changes the parameter of reference signal transmission density by allowing R(f) to vary across different frequency domain positions and over time. This dynamic adjustment of reference signal density parameters enables the system to adapt to changing channel conditions, maintaining adequate coverage where needed while reducing overhead in other regions, thus improving overall resource utilization efficiency

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12101272B2Methods and devices for determining channel resources for reference signals

Publication Date: 2024.09.24 ZTE CORP

AI summary

A method for determining a resource for a reference signal includes: determining, according to positions of N channel resource units used by a physical channel, R channel resource units from the N channel resource units, where both R and N are integers and 0≤R<N; and sending or receiving reference signals in the R channel resource units.