FBMC Preamble Reference Signal Design for Channel Estimation
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Solution Overview
Problem
Current 5G communication systems face challenges with spectrum efficiency, latency, and synchronization due to the limitations of Orthogonal Frequency Division Multiplexing (OFDM), particularly in low latency and IoT scenarios, where OFDM's high out-of-band leakage and sensitivity to carrier frequency offset reduce flexibility and increase complexity.
Innovation Solution
A preamble-based reference signal design for Filter-Bank Multi-Carrier (FBMC) modulation that utilizes self-interference to enhance channel estimation, allowing for efficient channel estimation and improved robustness, while being compatible with existing OFDM systems for multi-user, multi-cell communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If OFDM modulation is used in 5G communication systems, then wideband communication capability is achieved, but out-of-band leakage increases and carrier frequency offset sensitivity worsens
Solution Approach 1:
The patent changes the fundamental modulation parameter from OFDM to FBMC modulation scheme. FBMC uses filter bank based modulation with optimized prototype filters that provide better spectral containment, directly reducing out-of-band leakage while maintaining wideband communication capability. This parameter change addresses the contradiction by selecting a different modulation family with inherently better spectral properties.
Solution Approach 2:
The patent converts the harmful self-interference inherent in FBMC modulation into a beneficial signal for channel estimation. By designing preamble sequences that exploit the specific interference pattern of FBMC, the system transforms what was traditionally a detrimental effect into a useful resource for improving channel estimation accuracy and overall system performance.
2Ease of manufacture
If OFDM modulation is used, then simple implementation is achieved, but sensitivity to carrier frequency offset increases
Solution Approach 1:
The patent transitions from OFDM to FBMC modulation, changing the fundamental implementation approach. While FBMC has slightly more complex filtering requirements, it provides robustness against carrier frequency offset through its optimized prototype filters and reduced spectral leakage, thereby improving reliability without significantly compromising implementation simplicity.
3Reliability
If CP is inserted in OFDM to resist ISI, then signal reception without Inter-symbol Interference is achieved, but spectrum efficiency decreases
Solution Approach 1:
The patent extracts and removes the cyclic prefix component from the OFDM structure, replacing it with FBMC modulation. FBMC achieves ISI resistance through optimized filtering and time-frequency localization properties without requiring the redundant CP overhead, thereby eliminating the spectrum efficiency penalty while maintaining reliable signal reception in multipath environments.
Solution Approach 2:
The patent changes the modulation parameter from CP-OFDM to FBMC, which inherently provides better time-frequency localization. This parameter change enables the system to achieve the same ISI resistance without the CP overhead, directly improving spectrum efficiency by eliminating the redundant prefix symbols.
4Productivity
If FBMC modulation is used to improve spectrum efficiency, then out-of-band leakage is reduced, but self-interference must be managed
Solution Approach 1:
The patent converts the harmful self-interference inherent in FBMC modulation into a beneficial signal for channel estimation. By designing preamble sequences that exploit the specific interference pattern of FBMC, the system transforms what was traditionally a detrimental effect into a useful resource for improving channel estimation accuracy and overall system performance.
Solution Approach 2:
The system uses its own inherent self-interference pattern to serve the channel estimation function. The preamble design leverages the deterministic self-interference characteristics of FBMC to provide accurate channel state information, allowing the system to self-correct and improve performance using its own operational characteristics rather than requiring external correction mechanisms.
Data Source
AI summary
The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE).The application discloses methods and apparatuses for transmitting and receiving a preamble based reference signal. The method for transmitting a preamble based reference signal comprises: generating a main preamble sequence; generating an auxiliary preamble sequence, wherein, on a predefined resource, a synthesized signal of the main preamble sequence and the auxiliary preamble sequence is equal to a predefined preamble based reference signal; and transmitting the main preamble sequence and the auxiliary preamble sequence based on a filter-bank multi-carrier modulation. According to the embodiments of the application, the main preamble sequence and the auxiliary preamble sequence are appropriately designed so that the synthesized signal on the predefined resource is equal to the predefined preamble based reference signal. In this way, the predefined reference signal may be obtained at the receiving end by using the intrinsic interference of FBMC modulation, thereby making an efficient channel estimation.