RF Line Delay Compensation for MIMO Signal Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In indoor distributed communication systems, different radio frequency lines experience varying signal delays due to differing cable lengths, leading to misaligned time of air interface signals and poor data transmission performance in MIMO mode.
Innovation Solution
A method and device for delay compensation that involves a network device obtaining timing information from multiple radio frequency lines, determining a target timing reference, calculating compensation differences, and buffering signals based on these differences to align delays across lines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If independent radio frequency cables of different lengths are used to transmit signals from the signal source to the local network device, then the physical connection flexibility is improved, but the signal delay alignment deteriorates
Solution Approach 1:
The system performs preliminary delay measurement and compensation before MIMO signal transmission. The network device measures the delay difference between different radio frequency lines and pre-compensates for these differences, ensuring that signals arrive at the local network device aligned in time despite varying cable lengths.
Solution Approach 2:
The system changes the timing parameter of signals transmitted through different radio frequency lines. By adjusting the transmission timing of signals on each line based on measured delay differences, the system compensates for path length variations and achieves signal alignment at the receiving end.
2Device complexity
If signals from different radio frequency lines are transmitted without delay compensation, then the system complexity is reduced, but the data transmission performance in MIMO mode deteriorates
Solution Approach 1:
The system implements a feedback mechanism where the network device measures the actual delay difference between radio frequency lines and uses this measurement to adjust signal transmission timing. This closed-loop approach ensures optimal MIMO performance without requiring complex pre-configured cable length matching.
3Manufacturing precision
If delay compensation is performed using satellite time service information, then the signal delay alignment is improved, but the time consumption for synchronization increases
Solution Approach 1:
The system performs delay measurement and compensation in advance before MIMO transmission begins. By pre-aligning signals using satellite time service information, the system eliminates the need for continuous real-time synchronization during data transmission, reducing overall time loss.
Data Source
Figure 1a~2
Figure 3
Figure 4~5
AI summary
A delay compensation method is for performing delay compensation on signals of different radio frequency lines. The method in embodiments of this application includes: A first network device obtains at least one piece of first timing information of at least one radio frequency line of a second network device. The first network device determines target timing information based on the first timing information and second timing information. The target timing information indicates a reference value for performing compensation on a signal of the at least one radio frequency line. The first network device determines a compensation difference between the first timing information and the target timing information. The first network device performs, based on the at least one compensation difference, delay compensation on a signal of a radio frequency line that corresponds to the compensation difference and that is in the at least one radio frequency line.