NB-IoT Enhanced Reference Signal Transmission for Channel Estimation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
NB-IOT terminals face inadequate channel estimation and RRM measurement performance due to narrow bandwidth, leading to low demodulation efficiency in coverage-enhanced scenarios, making it difficult to meet measurement accuracy requirements.
Innovation Solution
A method is introduced where at least one first antenna port is determined for transmitting a demodulation reference signal and at least one second antenna port for transmitting an enhanced reference signal, with a power ratio set between them, and the enhanced reference signal is transmitted to improve channel estimation performance without excessive resource consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If existing LTE reference signals are applied in NB-IOT with narrow bandwidth, then the terminal can work on independent carrier or inside LTE bandwidth, but channel estimation performance becomes seriously insufficient under coverage enhancement scenarios
Solution Approach 1:
The patent applies local quality by designing reference signals with different densities for different coverage scenarios. Specifically, it introduces multiple reference signal density levels (normal density and enhanced density) that can be selectively applied based on the coverage enhancement requirement, thereby optimizing channel estimation performance locally for NB-IOT terminals in weak signal environments without affecting other scenarios
Solution Approach 2:
The patent changes the reference signal parameters by introducing a new reference signal density configuration parameter that allows dynamic adjustment of reference signal density. This parameter change enables the system to adapt reference signal density to coverage enhancement requirements, improving channel estimation accuracy for NB-IOT terminals in coverage-enhanced scenarios while maintaining compatibility with existing LTE systems
2Measurement precision
If reference signal density is increased to improve channel estimation, then measurement accuracy improves, but system resource consumption increases excessively
Solution Approach 1:
The patent applies dynamics by making reference signal density configurable and adaptable rather than fixed. It introduces a reference signal density parameter that can be dynamically adjusted based on coverage enhancement requirements and terminal capabilities, allowing the system to optimize the balance between measurement accuracy and resource consumption rather than using a static high-density configuration
Solution Approach 2:
The patent applies partial action by selectively increasing reference signal density only in specific subframes or resource blocks where coverage enhancement is needed, rather than uniformly increasing density across all resources. This partial enhancement approach improves measurement accuracy in critical areas while limiting overall resource consumption
Data Source
AI summary
The present disclosure provides a method and device for transmitting a reference signal, a method and device for receiving the same, the transmitting method includes: determining a first antenna port for transmitting a demodulation reference signal and a second antenna port for transmitting an enhanced reference signal, where the second antenna port and the first antenna port have an association; setting a transmitting power for the demodulation reference signal and a transmitting power for the enhanced reference signal; transmitting the demodulation reference signal and the enhanced reference signal to a terminal based on the first antenna port being determined for transmitting the demodulation reference signal and the second antenna port being determined for transmitting the enhanced reference signal, and according to the transmitting powers being set. Accordingly, when present technical solution is applied, a channel estimation performance and a RRM measurement performance of a NB-IOT terminal can be effectively improved.