Common Pilot Sequence for MU-MIMO Channel Estimation
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Solution Overview
Problem
Existing MU-MIMO systems under CoMP face challenges in achieving accurate channel estimation and interference suppression due to non-orthogonal DM-RSs across cells, leading to poor signal-to-interference-plus-noise ratios.
Innovation Solution
Implementing a common pilot sequence shared among paired users within a cell or collaborative area, rather than user-specific orthogonal DM-RSs, to enhance channel estimation accuracy and reduce multi-user interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If user-specific orthogonal DM-RS are used in MU-MIMO CoMP system, then orthogonality between users is achieved, but channel estimation accuracy deteriorates and multi-user interference cannot be eliminated
Solution Approach 1:
The patent merges the pilot sequences of multiple users into a single common pilot sequence that is shared across all users in the MU-MIMO CoMP system. This eliminates the need for user-specific orthogonal DM-RS and allows all users to use the same pilot for channel estimation, thereby improving channel estimation accuracy while maintaining multi-user support through the collaborative transmission mechanism
Solution Approach 2:
The common pilot sequence serves multiple functions simultaneously: it acts as the reference signal for channel estimation for all users in the system, enables collaborative transmission across multiple cells, and supports MU-MIMO operation. This universal pilot sequence replaces the traditional user-specific DM-RS and provides a unified reference for multi-user channel estimation in the CoMP system
2Ease of manufacture
If existing DM-RS is adopted in MU-MIMO CoMP system, then transmission simplicity is maintained, but signal-to-interference-plus-noise ratio deteriorates due to poor channel estimation
Solution Approach 1:
The patent changes the fundamental parameter of the pilot sequence from user-specific to common/shared across all users. This parameter change enables improved channel estimation accuracy which directly enhances the signal-to-interference-plus-noise ratio, while the implementation remains relatively simple by utilizing the existing common pilot structure already present in the system
3Measurement precision
If common pilot sequence is used for paired users, then channel estimation accuracy is improved, but pilot sequence orthogonality is sacrificed
Solution Approach 1:
The patent merges multiple user-specific pilot sequences into a single common pilot sequence that is shared across all users in the MU-MIMO CoMP system. This eliminates the need for user-specific orthogonal DM-RS and allows all users to use the same pilot for channel estimation, thereby improving channel estimation accuracy while maintaining multi-user support through the collaborative transmission mechanism
Solution Approach 2:
The patent converts the potential harm of non-orthogonal pilots into a benefit by using the common pilot sequence to enable accurate channel estimation for all users simultaneously. The loss of traditional orthogonality is compensated by the collaborative transmission and interference suppression capabilities of the CoMP system, which can effectively manage the interference introduced by shared pilots
Data Source
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AI summary
Embodiments of the present invention provide a multi-user interference suppression method, terminal and base station, including: performing layer mapping on and precoding service data of each of paired users, to obtain precoded output data ;; and mapping the precoded output data ; and a common pilot sequence to a port of an antenna array, for sending to each user by using the antenna array. Correspondingly, the embodiments of the present invention further provide a data receiving method, base station and terminal. By using a common pilot sequence based on the paired users, the same pilot sequence is used for each user in the paired users of a cell or a collaborative area, which is different from the technical solution in the prior art where a user-specific pilot is used, and pilots of different users must be orthogonal. Therefore, the number of paired users is not limited by the number of orthogonal pilot sequences, thereby better supporting the CoMP mode, and improving accuracy of channel estimation.