SRS Antenna Port Selection for 1T4R Terminal Devices
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Solution Overview
Problem
Current LTE protocols are unable to support SRS antenna selection for four antenna ports, which is necessary for complete channel information acquisition in terminal devices with 1T4R antenna configurations.
Innovation Solution
A method for transmitting a sounding reference signal (SRS) that involves determining an index corresponding to an antenna port for SRS transmission based on SRS configuration information, SRS bandwidth configuration parameters, and sequence number of SRS transmissions, allowing for effective antenna selection among four antenna ports.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the existing LTE protocol antenna selection formula is used, then 1T2R antenna selection is supported, but 1T4R antenna selection cannot be supported
Solution Approach 1:
The patent modifies the antenna selection formula by changing the parameter Λ from 2 to 4, enabling support for 1T4R antenna selection. The formula a(nSRS) = floor(nSRS/Λ) mod Λ is generalized to accommodate any number of antenna ports, transforming the protocol from 1T2R to 1T4R capability while maintaining the same mathematical structure.
2Loss of information
If antenna switching is performed to transmit SRS through multiple antenna ports, then complete channel information can be obtained, but the number of transmissions required increases
Solution Approach 1:
The patent implements periodic antenna port switching where the terminal device cycles through Λ antenna ports in a systematic sequence. By using the formula a(nSRS) = floor(nSRS/Λ) mod Λ, the system ensures that each antenna port is selected in a periodic pattern, allowing complete channel information to be acquired efficiently within a limited number of transmissions.
3Measurement precision
If four antenna ports are configured for SRS transmission, then channel sounding accuracy is improved, but the complexity of antenna selection increases
Solution Approach 1:
The patent creates a universal antenna selection formula that can handle any number of antenna ports Λ. This multi-functional approach allows the same formula structure to work for both 1T2R (Λ=2) and 1T4R (Λ=4) configurations, as well as potentially other configurations, thereby improving channel sounding accuracy without proportionally increasing selection complexity.
Data Source
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AI summary
A method for transmitting a sounding reference signal and a terminal device are provided. The method includes: receiving, by the terminal device, SRS configuration information from a network device; determining, based on one or more of an SRS bandwidth configuration parameter, a sequence number nSRS of a quantity of SRS transmissions, a quantity Λ of antenna ports, and the received SRS configuration information, an index a(nSRS) corresponding to an antenna port used to transmit an SRS; selecting the antenna port with the index of a(nSRS) from indexes corresponding to the Λ antenna ports; and transmitting the SRS through the antenna port with the index of a(nSRS) during an nSRSth SRS transmission. nSRS is an integer greater than or equal to 0, Λ is a positive integer greater than or equal to 4, and a symbol * indicates a multiplication operation. According to the method, SRS antenna selection of four antenna ports can be supported.