SRS Capacity in 5G UpPTS via Time-Domain Multiplexing
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Solution Overview
Problem
The existing 5G communication systems face challenges in SRS capacity enhancement, particularly when using FD-MIMO with increased UE transmission antennas and frequency hopping, leading to compatibility issues with legacy UEs and inefficient channel estimation performance.
Innovation Solution
Increasing the number of SC-FDMA symbols for SRS transmission in the UpPTS, along with a radio resource control (RRC) and distributed computing infrastructure (DCI) design method for trigger types 0 and 1, to enhance SRS capacity without compromising compatibility with legacy UEs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the number of transmission antennas of a UE is increased to 4 and frequency hopping is used, then the SRS capacity is enhanced, but it becomes impossible to support up to 16 UEs
Solution Approach 1:
The patent extends SRS transmission from a single symbol to multiple symbols (up to 8 symbols) in the UpPTS, utilizing the time dimension. This allows more UEs to share the SRS resources by transmitting in different symbol positions, thereby supporting up to 16 UEs while maintaining 4 transmission antennas and frequency hopping.
2Quantity of substance
If SRS is transmitted at the position of the demodulation reference signal (DMRS) of the physical uplink shared channel (PUSCH), then SRS capacity is enhanced, but channel estimation performance is degraded
Solution Approach 1:
The patent extracts SRS transmission from the PUSCH region and places it in the UpPTS region with multiple dedicated symbols. This separation ensures that SRS and DMRS do not overlap in time or frequency, preventing interference and maintaining accurate channel estimation while still achieving SRS capacity enhancement through multiple symbols.
3Quantity of substance
If the number of SRS comb types is increased, then SRS capacity is enhanced, but orthogonality with legacy SRS is broken
Solution Approach 1:
Instead of increasing comb types in the frequency domain, the patent utilizes the time domain by allocating multiple SRS symbols in the UpPTS. This approach enhances SRS capacity through time-division multiplexing while maintaining frequency-domain comb structures that are compatible with legacy UEs, ensuring orthogonality and coexistence.
4Quantity of substance
If up to 8 SC-FDMA symbols are used for SRS transmission in one special subframe, then SRS capacity is enhanced, but the subframe structure becomes more complex
Solution Approach 1:
The patent configures the UpPTS to serve dual purposes: maintaining its traditional function for random access and uplink synchronization while simultaneously supporting up to 8 SRS symbols for enhanced SRS capacity. This multi-functionality is achieved through flexible configuration parameters that allow the same time resources to serve multiple objectives without requiring separate dedicated structures.
Data Source
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AI summary
The present disclosure relates to a 5G or pre-5G communication system for supporting a data rate higher than that of the 4G system. A method by a terminal in a wireless communication system according to the present disclosure includes receiving a first message comprising first information indicating a number of symbols in an uplink pilot time slot (UpPTS) region, identifying at least one symbol for transmitting a sounding reference signal (SRS) based on the first information, and transmitting the SRS.