FBMC Pilot Symbol Group Interference Cancellation
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Solution Overview
Problem
Current MIMO-FBMC pilot sending methods face challenges with high pilot overheads and power increases, particularly in MIMO cases, which affect channel estimation performance due to inherent interference in FBMC systems.
Innovation Solution
An FBMC-based pilot sending method is introduced, where a pilot symbol group with two auxiliary and two primary pilot symbols is inserted at specific time-frequency resource locations, with auxiliary pilot symbols calculated based on interference coefficients and data symbol values to cancel interference, reducing pilot overheads and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the IAM method is used for pilot sending, then channel estimation can be performed, but pilot overheads increase and spectral efficiency decreases
Solution Approach 1:
The patent divides the pilot structure into primary pilots and auxiliary pilots with specific roles. Primary pilots are used for channel estimation while auxiliary pilots are specifically designed to cancel interference. This segmentation allows the system to use fewer overall pilots compared to IAM while maintaining estimation accuracy.
Solution Approach 2:
The patent introduces auxiliary pilots as intermediary elements that mediate between data symbols and primary pilots. These auxiliary pilots are calculated based on interference coefficients and data symbol values, and they actively cancel interference at primary pilot locations, enabling accurate channel estimation with reduced pilot overhead.
2Quantity of substance
If the APM method is used for pilot sending, then pilot overheads are reduced, but power increase occurs due to auxiliary pilots
Solution Approach 1:
The patent optimizes the calculation of auxiliary pilot values by using interference coefficients obtained from multiplex converter response data and specific formulas. This parameter optimization ensures that auxiliary pilots are calculated with minimal power consumption while achieving effective interference cancellation, thus reducing overall power increase compared to conventional APM methods.
3Productivity
If FBMC technology is used, then frequency spectrum utilization is improved, but inherent interference pollutes pilot symbols at the receive end
Solution Approach 1:
The patent applies preliminary action by calculating auxiliary pilots before transmission based on known interference coefficients and data symbol values. This pre-calculated interference cancellation is embedded in the auxiliary pilot values, so when received, the primary pilots are already protected from interference pollution, enabling accurate channel estimation despite FBMC's inherent interference.
Data Source
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AI summary
The present invention provides an FBMC-based pilot sending method, a channel estimation method, and a related apparatus. The FBMC-based pilot sending method includes: for each transmit antenna port, inserting a pilot symbol group at four consecutive time-frequency resource locations, where the pilot symbol group includes two auxiliary pilot symbols and two primary pilot symbols; calculating a transmit value of each auxiliary pilot symbol in the pilot symbol group according to obtained interference coefficient values and obtained transmit values of data symbols at time-frequency resource locations in a time-frequency resource location range in which each primary pilot symbol is interfered with; and sending the pilot symbol group, where the pilot symbol group includes the calculated transmit values of the auxiliary pilot symbols. Interference caused by data symbols at other time-frequency resource locations to the primary pilot symbols is cancelled for receive values that are obtained by a receive end and are at time-frequency resource locations at which the primary pilot symbols are located. In addition, the channel estimation method can reduce pilot overheads and a power increase caused by an auxiliary pilot symbol, and improve channel estimation performance.