Distributed MIMO Signal Synchronization via Phase Adjustment
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Solution Overview
Problem
In distributed MIMO technology, signal interference occurs due to asynchronous time between transmitters, leading to measurement errors and time offsets, which hinder effective signal transmission.
Innovation Solution
A signal sending method that generates a first data signal based on channel state information, using the phase of a measurement signal from a primary transmitter and the phase of a data signal from the same transmitter to adjust the phase of a secondary transmitter's signal, thereby eliminating detection delays and achieving time synchronization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If distributed MIMO technology is used to send signals by multiple spatially independent transmitters, then data transmission efficiency is improved, but time synchronization between transmitters deteriorates due to asynchronous clock generation from local crystal oscillators
Solution Approach 1:
The patent merges the clock generation function from multiple distributed transmitters into a unified system by having all transmitters synchronize to a reference clock signal from a primary transmitter. This combines the independent clock sources into a coordinated system, achieving time synchronization while maintaining the distributed architecture for improved data transmission efficiency.
Solution Approach 2:
The patent implements feedback mechanisms where transmitters measure phase differences of received signals and adjust their transmission phases accordingly. Secondary transmitters measure the phase of signals received from the primary transmitter and feed back this information to adjust their own transmission timing, creating a closed-loop synchronization system that maintains time alignment across distributed transmitters.
2Reliability
If phase adjustment is performed directly using measured phase of received signal, then time synchronization is attempted, but measurement errors cause large phase adjustment errors and signal interference
Solution Approach 1:
The patent performs preliminary phase measurement and compensation actions before actual data transmission. Transmitters conduct phase measurements during dedicated measurement periods and calculate compensation values in advance, applying these adjustments before the main transmission occurs. This preliminary action allows the system to prepare synchronization corrections without the pressure of real-time transmission requirements.
Solution Approach 2:
The patent introduces cushioning mechanisms by using multiple measurement samples and averaging techniques to reduce the impact of random measurement errors. The system performs repeated phase measurements and uses statistical processing to cushion against individual erroneous measurements, providing a more robust basis for phase adjustment decisions.
3Productivity
If multiple transmitters send signals simultaneously at the same frequency, then signal transmission capacity is improved, but signal interference increases due to time offsets
Solution Approach 1:
The patent changes the time parameter of signal transmission by adjusting the transmission timing of each transmitter based on measured phase differences. Transmitters modify their transmission time offsets to align with the reference transmitter, transforming the time synchronization parameter to eliminate interference while maintaining simultaneous transmission capability for improved signal transmission capacity.
Data Source
AI summary
The present disclosure relates to signal sending methods and apparatus. One example method includes generating a first data signal based on channel state information, receiving a second data signal sent by a primary transmitter, determining a phase of the second data signal, and sending the first data signal based on a phase of a first measurement signal sent by the primary transmitter and the phase of the second data signal sent by the primary transmitter.