Terminal Signal Processing for CoMP Time Difference Adjustment
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Solution Overview
Problem
In the inter-eNB scenario of CoMP, it is challenging to accurately control the time difference or phase difference of arrival between downlink signals from multiple cells, leading to deteriorated CoMP performance due to inaccurate CSI-RS reflections and low accuracy in calculating time or phase differences by the terminal.
Innovation Solution
A signal processing method that involves receiving control signaling scrambled with CoMP-RNTI, determining channel state information between coordinated and serving base stations, acquiring and sending adjustment information about time or phase differences to the serving base station, which adjusts the signal's timing, phase, or pre-coding using RM coding, thereby reducing the time or phase difference between signals received by the terminal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If CSI-RS is used to calculate time difference or phase difference between cells, then the terminal can obtain timing information, but the accuracy is low because CSI-RS does not reflect the current channel state
Solution Approach 1:
The patent applies preliminary action by having the terminal calculate time difference or phase difference information in advance based on CSI-RS, and then uses this pre-calculated information to adjust uplink transmission timing. This allows the system to prepare timing adjustment data before actual data transmission, improving the accuracy of timing synchronization without requiring real-time channel state measurements.
2Reliability
If the terminal sends timing adjustment information to the serving cell, then the serving cell can coordinate with the coordinated cell, but the information transmission requires additional signaling overhead
Solution Approach 1:
The patent uses the PUCCH channel as an intermediary to transmit timing adjustment information from the terminal to the serving cell. By leveraging the existing uplink control channel infrastructure, the system can convey precise timing/phase difference measurements without requiring dedicated signaling resources, thus maintaining high coordination reliability while minimizing additional signaling overhead.
3Area of stationary object
If multiple cells transmit data to the terminal simultaneously in inter-eNB scenario, then network coverage is expanded, but time difference or phase difference of arrival cannot be controlled within a relative low range
Solution Approach 1:
The patent implements feedback by having the terminal measure and report time difference or phase difference information between signals from different cells. The serving cell uses this feedback to adjust the transmission timing or phase of the coordinated cell, creating a closed-loop control system that maintains synchronization accuracy even in inter-eNB scenarios where geographic separation makes precise timing control challenging.
Data Source
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AI summary
Embodiments of the present invention provide a signal processing method and a terminal. The technical field of communications is involved. The problem that time difference or phase difference between signals which are sent by at least two cells and received by a terminal is relative big in the inter-eNB scenario is solved. The method includes: receiving a control signal; determining channel state information between a coordinated base station and the terminal, and between the serving base station and the terminal; acquiring information about time difference or information about phase difference of arrival between signals sent by the coordinated base station and the serving base station at the terminal according to the channel state information; and sending the adjustment information to the serving base station, so that the serving base station adjusts the sending time, phase, or pre-coding manner of the signal according to the adjustment information. It is applied in cell multipoint coordinated transmission.