CSI-RS Sequence Initialization for Wireless Systems
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Solution Overview
Problem
Current mobile communication systems face challenges in supporting high-speed data services, increased user connections, low latency, and energy efficiency, particularly in configuring initialization values for channel state information-reference signals (CSI-RS) in new radio (NR) systems, where existing methods are inadequate for various subcarrier spacings and CSI-RS sequence management.
Innovation Solution
A method is introduced for configuring initialization values of CSI-RS sequences in NR systems using specific scrambling IDs and modulo operations, allowing unique sequence initialization values for each OFDM symbol within a 10ms radio frame, and applying identical sequences within code division multiplexing (CDM) groups to improve CSI acquisition and beam management performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the same initialization value is used for CSI-RS sequences across different OFDM symbols, then device complexity is reduced, but sequence reuse occurs causing interference and performance degradation
Solution Approach 1:
The initialization value is made dynamic by incorporating the OFDM symbol index variable l into the calculation formula. This allows the initialization value to automatically adapt to different OFDM symbols within a slot, ensuring uniqueness without requiring manual configuration for each symbol. The dynamic parameter l changes with each OFDM symbol, thereby generating distinct initialization values.
Solution Approach 2:
The patent changes the parameters used in the initialization value calculation from static values to dynamic values that vary with OFDM symbol index. By introducing the variable l (OFDM symbol index) into the formula, the system transforms a static initialization approach into a dynamic one, where the initialization value evolves based on the current OFDM symbol position.
2Reliability
If different initialization values are configured for each OFDM symbol, then sequence uniqueness is improved, but device complexity and configuration overhead increase
Solution Approach 1:
A single unified formula is designed to serve multiple OFDM symbols within a slot. Instead of requiring separate initialization values for each symbol, the universal formula with variable l generates appropriate initialization values for all symbols in a slot, reducing configuration overhead while maintaining uniqueness.
Solution Approach 2:
The initialization value calculation is made self-service by incorporating the OFDM symbol index l directly into the formula. The system automatically generates unique initialization values for each symbol without requiring external configuration or manual intervention, as the variable l naturally provides the differentiation needed.
3Ease of operation
If sequence initialization does not consider subcarrier spacing variations, then configuration simplicity is maintained, but sequence reuse occurs in NR systems with various subcarrier spacings
Solution Approach 1:
The initialization value calculation is made dynamic by incorporating the slot index n_s and OFDM symbol index l, which automatically adapt to different subcarrier spacing configurations. In NR systems, different subcarrier spacings result in different numbers of slots per frame and different slot structures, and these dynamic indices automatically adjust to maintain sequence uniqueness regardless of the subcarrier spacing being used.
Data Source
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AI summary
Provided is a method of determining an initialization value of a sequence in a wireless communication system. Specifically, a method performed by evolveda base station includes generating a first sequence of a channel state information-reference signal (CSI-RS) based on a pseudo-random sequence; and transmitting the first sequence on resource element (RE)s.