Access Network Device Timing Adjustment for Paired Band Interference
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Solution Overview
Problem
In LTE/LTE-A communications systems, the difference in downlink and uplink service volumes across cells using paired frequency bands leads to interference issues due to transmission delays, which existing interference cancellation technologies struggle to resolve effectively, especially when the downlink signal from a serving cell interferes with uplink signals in neighboring cells.
Innovation Solution
The method involves determining a timing adjustment amount by access network devices to align the timing of downlink signals with uplink signals in neighboring cells, allowing the access network devices to cancel interference by ensuring the time difference between symbols is within the cyclic prefix length, thereby resolving intersymbol and inter-carrier interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If flexible duplex technology is used to improve network resource utilization, then service requirement satisfaction is improved, but interference between neighboring cells increases
Solution Approach 1:
The access network device performs preliminary timing adjustment by determining a timing adjustment amount based on downlink signal transmission timing and neighboring cell uplink signal reception timing. This preliminary action ensures that when the downlink signal reaches the neighboring cell, it arrives at the correct time slot to avoid interfering with uplink transmissions, thereby resolving the interference issue while maintaining flexible duplex benefits
2Object-affected harmful factors
If downlink transmission timing is adjusted to align with neighboring cell uplink timing, then interference cancellation is improved, but transmission delay compensation complexity increases
Solution Approach 1:
The access network device changes the transmission timing parameter by calculating a timing adjustment amount based on the difference between downlink signal transmission timing and neighboring cell uplink signal reception timing. This parameter adjustment ensures proper alignment without requiring complex interference cancellation algorithms, simplifying the overall system complexity while improving interference cancellation effectiveness
3Object-affected harmful factors
If timing adjustment is applied to align symbols within cyclic prefix, then intersymbol and inter-carrier interference are resolved, but timing precision requirements increase
Solution Approach 1:
The access network device performs self-adjustment by automatically calculating the timing adjustment amount based on its own downlink transmission timing and neighboring cell uplink reception timing information. This self-service mechanism achieves precise timing alignment within the cyclic prefix without requiring external timing synchronization or complex measurement systems, thereby resolving interference while maintaining practical timing precision requirements
Data Source
AI summary
An information receiving method, an information sending method, and a device are provided. Under these methods, a timing adjustment amount can be determined by a first access network device. The timing adjustment amount is an adjustment amount between a first timing at which the first access network device sends a first downlink signal to a first terminal device on a first frequency band and a second timing at which the first access network device sends a second downlink signal to the first terminal device on a second frequency band. The first frequency band and the second frequency band are paired frequency bands. First indication information can be sent, by the first access network device, to the first terminal device. The first indication information indicates the timing adjustment amount.