Uplink Demodulation Reference Signal Scheduling in NB-IoT
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current NB-IoT systems cannot reuse uplink demodulation reference signals due to differences in scheduling between NB-IoT and LTE systems, leading to inefficiencies in data transmission.
Innovation Solution
A method and apparatus for scheduling uplink demodulation reference signals in units of sub-carriers within a time-frequency unit, allowing for flexible generation, mapping, and transmission of these signals based on specific parameters such as sub-carrier spacing, time-domain offsets, and sequence lengths, enabling efficient data transmission in NB-IoT systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If NB-IoT schedules uplink data on a basis of sub-carrier, then it can achieve finer granularity resource allocation and improve spectral efficiency, but it cannot reuse the uplink demodulation reference signal in the LTE system, leading to increased system complexity and loss of compatibility
Solution Approach 1:
The patent segments the reference signal generation process into multiple independent components: base sequence generation, cyclic shift application, and resource element mapping. This segmentation allows the system to handle sub-carrier-based scheduling independently for each component, enabling fine-grained resource allocation while maintaining manageable system complexity through modular design.
Solution Approach 2:
The patent changes key parameters of the reference signal to adapt to sub-carrier-based scheduling: it modifies the sequence length to match the number of sub-carriers, adjusts the cyclic shift values, and changes the mapping pattern from resource-block-based to sub-carrier-based. These parameter changes enable compatibility with NB-IoT's scheduling granularity while maintaining the fundamental structure of LTE reference signals.
2Adaptability or versatility
If NB-IoT uses different scheduling basis from LTE, then it can optimize resource allocation for narrowband operations, but it loses the ability to reuse LTE uplink demodulation reference signals, resulting in loss of compatibility and increased implementation difficulty
Solution Approach 1:
The patent creates a universal reference signal generation framework that can operate with different scheduling granularities. By defining the reference signal parameters (sequence length, cyclic shift, mapping pattern) as configurable variables rather than fixed values, the system can adapt to both sub-carrier-based and resource-block-based scheduling, providing multi-functionality without requiring separate reference signal designs for different scheduling modes.
Data Source
AI summary
The present disclosure provides a method and an apparatus for uplink signal transmission. The method includes: generating an uplink demodulation reference signal to be transmitted within a first time-frequency unit, the first time-frequency unit including one or more sub-carriers in frequency domain; mapping the uplink demodulation reference signal to a first time-frequency position of the first time-frequency unit; and transmitting the uplink demodulation reference signal within the first time-frequency unit and uplink data corresponding to the uplink demodulation reference signal.