FCP-OFDM Filter Index Selection for Spectral Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communication systems, particularly OFDM schemes, face challenges with time-frequency synchronization and out-of-band emission (OOBE), which limit their performance and efficiency, especially in frequency-exhausted states and asynchronous situations.
Innovation Solution
The method involves a user equipment selecting a filter index to maximize the Signal to Interference-Plus-Noise Ratio (SINR) or Signal to Leakage-and-Noise Ratio (SLNR) within a predefined filter book for resource blocks (RB) or subbands and transmitting this information to a base station, enabling adaptive filtering in a Filtered Cyclic Prefix-Orthogonal Frequency Division Multiplexing (FCP-OFDM) system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If OFDM scheme is used, then spectral efficiency is improved, but time-frequency synchronization restriction and out-of-band emission problems worsen
Solution Approach 1:
The patent changes the fundamental parameters of the waveform by transitioning from traditional OFDM to FCP-OFDM, which modifies the spectral confinement characteristics and time-domain properties. This parameter change allows the system to achieve both good spectral efficiency and relaxed synchronization requirements simultaneously.
Solution Approach 2:
The patent introduces dynamic filter selection where the base station adaptively chooses filtering characteristics from a predefined set based on channel conditions and interference levels. This dynamic adaptation enables the system to optimize performance for different operational scenarios, resolving the contradiction between spectral efficiency and synchronization requirements.
2Ease of manufacture
If traditional OFDM is used, then implementation simplicity is maintained, but out-of-band emission performance deteriorates
Solution Approach 1:
The patent segments the frequency spectrum by applying different filtering characteristics to different resource blocks or subbands. This segmentation allows selective control of out-of-band emissions in specific frequency regions while maintaining simple OFDM implementation in other regions, thus resolving the contradiction between implementation simplicity and OOBE performance.
Solution Approach 2:
The patent introduces filtering characteristics as an intermediary element between the simple OFDM structure and the requirement for low out-of-band emission. These filters act as mediators that suppress harmful emissions without fundamentally changing the simple OFDM implementation, thus resolving the contradiction.
3Reliability
If adaptive filtering is implemented, then reception performance in asynchronous conditions is improved, but system complexity increases
Solution Approach 1:
The patent implements dynamic filter selection where the base station adaptively chooses filtering characteristics from a predefined set based on channel conditions and interference levels. This dynamic adaptation enables the system to optimize performance for different operational scenarios without requiring complex real-time filter design, thus resolving the contradiction between reception performance and system complexity.
Solution Approach 2:
The patent changes the system parameters by introducing a predefined set of filtering characteristics that can be selectively applied. This parameter change allows adaptive optimization of reception performance while avoiding the complexity of designing and managing continuous filter parameters, thus resolving the contradiction between reliability and device complexity.
4Adaptability or versatility
If filter book feedback is transmitted, then base station can optimize filtering, but feedback overhead increases
Solution Approach 1:
The patent implements partial feedback by reporting filter quality information only for specifically instructed resource blocks or subbands rather than all allocated resources. This partial action reduces feedback overhead while still providing the base station with sufficient information to optimize filtering in critical regions, thus resolving the contradiction between adaptability and feedback overhead.
Solution Approach 2:
The patent applies local quality by providing detailed filter quality information only for specific resource blocks or subbands where optimization is most needed, rather than uniformly across all resources. This localized approach reduces overall feedback overhead while maintaining filtering optimization capability in critical areas, thus resolving the contradiction between adaptability and feedback overhead.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method by which a terminal transmits feedback information in a wireless communication system can comprise the steps of: selecting a filter index for maximizing a signal to interference-plus-noise (SINR) or a signal to leakage-and-noise ratio (SLNR) in a filter book defined in advance for each resource block (RB) or subband; and transmitting, to a base station, feedback information including the selected filter index for each RB or subband.