Channel Estimation Using Equivalent Pilot Sequence for Frequency Offset Compensation
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Solution Overview
Problem
In high-speed scenarios within the LTE system, significant frequency offsets lead to sampling errors in the frequency domain, causing interference between sub-carriers and resulting in inaccurate channel estimation, which degrades receiver performance, as existing channel estimation algorithms fail to account for frequency offsets effectively.
Innovation Solution
Compensate for the frequency offset of the locally generated reference signal sequence using a historical valid frequency offset, determining an equivalent pilot sequence and transforming it into the frequency domain to improve correlation accuracy, thereby reducing secondary path detection and enhancing channel estimation accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a common channel estimation algorithm is applied in high-speed scenarios, then the algorithm can be implemented with standard processing, but significant frequency offset causes sampling errors and interference between sub-carriers, resulting in inaccurate channel estimation
Solution Approach 1:
The patent applies preliminary action by pre-compensating the local pilot sequence using historical frequency offset information before correlation processing. The equivalent pilot sequence is generated in advance by applying phase rotation based on historical frequency offset, which eliminates the need for complex real-time frequency offset estimation and correction during channel estimation, thus maintaining ease of operation while improving accuracy in high-speed scenarios
Solution Approach 2:
The patent changes the parameter of the pilot sequence by transforming it into an equivalent pilot sequence that incorporates frequency offset compensation. By modifying the pilot sequence parameters (applying phase rotation based on historical frequency offset), the system adapts to high-speed conditions without fundamentally changing the channel estimation algorithm structure, resolving the contradiction between ease of operation and measurement precision
2Measurement precision
If frequency offset compensation is performed using historical valid frequency offset, then channel estimation accuracy is improved in high-speed scenarios, but additional processing steps are required to determine equivalent pilot sequence
Solution Approach 1:
The patent uses preliminary action by performing frequency offset compensation in advance using historical frequency offset information. The equivalent pilot sequence is pre-generated with phase rotation applied based on historical data, which simplifies the overall processing complexity compared to real-time frequency offset estimation and correction methods, thus improving measurement precision without significantly increasing device complexity
Solution Approach 2:
The patent applies copying by creating an equivalent pilot sequence that replicates the effect of frequency offset compensation. Instead of directly correcting frequency offset in the received signal, the system generates a compensated version of the pilot sequence that when correlated with the received signal, achieves the same effect as frequency offset correction, thereby improving accuracy while maintaining relatively simple processing complexity
3Ease of operation
If original local pilot sequence is used in correlation algorithm, then processing is straightforward, but significant frequency offset causes significant error in channel estimation
Solution Approach 1:
The patent changes the parameters of the local pilot sequence by applying phase rotation based on historical frequency offset to create an equivalent pilot sequence. This parameter modification allows the correlation processing to remain straightforward while significantly improving channel estimation accuracy in high-speed scenarios with large frequency offsets, thus resolving the contradiction between ease of operation and measurement precision
Data Source
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AI summary
Disclosed are a channel estimation method and device for improving accuracy of channel estimation so as to improve the performance of a receiver. The present application provides a channel estimation method, comprising: determining an equivalent pilot sequence by means of a historical effective frequency offset value; determining a sequence for multiple correlation by using the equivalent pilot sequence; and performing multiple correlation calculation of channel estimation by using the sequence for multiple correlation.