SRS Transmission Symbol Allocation for Channel Aging Reduction
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Solution Overview
Problem
In 5G communication systems, the channel aging effect intensifies, leading to shortened coherence times and increased latency in uplink/downlink channel reciprocity-based transmission processes, which are not effectively addressed by existing technologies, particularly due to limitations in the number of uplink reference signals and channel state information acquisition.
Innovation Solution
A method is introduced where a network device determines multiple symbols for transmitting channel SRSs within a single uplink subframe, with indication information sent to terminal devices specifying the symbol for SRS transmission, allowing for reduced channel aging influence by optimizing the timing and resource allocation for SRS and downlink data transmission based on channel aging speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If SRS is configured only on the last symbol of each uplink subframe in 4G LTE system, then the system structure is simple and easy to implement, but the channel aging effect becomes serious in 5G massive MIMO system due to increased latency
Solution Approach 1:
The uplink subframe is segmented into multiple symbols, and SRS transmission is allocated to multiple specific symbols rather than only the last symbol. This segmentation allows the SRS to be transmitted at multiple time points within the same subframe, reducing the latency between channel estimation and data transmission, thereby mitigating channel aging effects while maintaining systematic implementation
Solution Approach 2:
SRS transmission is performed in advance at multiple symbols before the data transmission symbol within the same uplink subframe. This preliminary action ensures that channel state information is obtained closer to the actual data transmission moment, improving channel estimation accuracy and reducing channel aging impact
2Measurement precision
If multiple symbols are used for SRS transmission in 5G system, then channel aging influence is reduced and channel estimation accuracy is improved, but the device complexity and resource allocation complexity increase
Solution Approach 1:
Different terminal devices are assigned to different symbols for SRS transmission within the same uplink subframe based on their specific channel characteristics and requirements. This local differentiation allows each terminal to have optimized SRS transmission timing while the network device manages multiple symbols systematically, reducing overall complexity
Solution Approach 2:
The network device dynamically determines and configures which symbols within the uplink subframe will be used for SRS transmission by different terminal devices. This dynamic allocation adapts to varying channel conditions and terminal requirements, optimizing channel estimation accuracy while maintaining manageable system complexity through flexible resource management
Data Source
AI summary
Disclosed in the present invention are a method for transmitting a sounding reference signal (SRS), a network device and a terminal device. The method comprises: a network device determining multiple symbols used for transmitting an SRS in a first uplink subframe; the network device transmitting first indication information to each of multiple terminal devices, the first indication information being used for indicating a symbol of the multiple symbols corresponding to said each terminal device, a first terminal device of the multiple terminal devices corresponding to a first symbol of the multiple symbols, the first symbol being used for transmitting the SRS of the first terminal device. Thus, during the transmission between the network device and the terminal device using uplink-downlink channel reciprocity, influences caused by channel characteristic aging can be reduced.