SRS Resource Allocation in LTE-A Systems
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Solution Overview
Problem
The LTE-A system faces a reduction in user capacity when SRS is transmitted by multiple antennas, contradicting the requirement of maintaining user capacity equivalent to LTE, due to increased SRS resources needed per UE.
Innovation Solution
The eNB allocates SRS bandwidth with 4n Resource Blocks and equally divides the time domain sequence into t portions, configuring a time domain RePetition Factor (RPF) and allowing use of one or more cyclic shifts, with signaling to notify the terminal of RPF, frequency comb location, and cyclic shift, ensuring 48 × n × RPF can be divided by 12, and L≤t, thereby increasing available SRS resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If SRS is transmitted by multiple antennas in LTE-A system, then channel measurement capability is improved, but user capacity is reduced due to increased SRS resources needed per UE
Solution Approach 1:
The patent segments the SRS resource allocation into multiple independent dimensions: frequency domain (resource blocks), time domain (repetition factor), and code domain (cyclic shifts). By dividing the SRS bandwidth into multiple resource blocks and allowing multiple repetitions per UE, the system can support multiple antennas per UE while maintaining overall user capacity through efficient resource sharing across multiple UEs.
2Measurement precision
If SRS bandwidth is increased to support multiple antennas, then measurement accuracy is improved, but available resources for other UEs are reduced
Solution Approach 1:
The patent introduces a time domain dimension through the repetition factor, allowing SRS resources to be allocated across both frequency and time domains. This multi-dimensional allocation enables the system to provide sufficient measurement resources for multiple-antenna UEs while maintaining user capacity by distributing resources across different time slots and frequency blocks.
3Reliability
If more cyclic shifts are allocated to each UE for multiple antenna support, then channel state information quality is improved, but total number of multiplexed UEs is reduced
Solution Approach 1:
The patent combines multiple resource allocation dimensions (frequency blocks, time repetitions, and cyclic shifts) to create a comprehensive resource pool. By merging these dimensions, the system can allocate appropriate resources to each UE based on their specific needs while maintaining overall system capacity through efficient sharing across all dimensions.
Data Source
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AI summary
A system and a method for allocating Sounding Reference Signal (SRS) resources are provided in the present invention, the method includes: an e-Node-B (eNB) allocating a SRS bandwidth with 4n Resource Blocks (RBs) to a terminal, and equally dividing a time domain sequence of a SRS into t portions in the SRS bandwidth; the eNB configuring a time domain RePetition Factor (RPF) used by the UE, and the eNB configuring the UE to use one or more cyclic shifts in L cyclic shifts for each UE; then the eNB notifying the UE of a value of the time domain RPF, a location of a used frequency comb and a used cyclic shift by signaling, wherein n is a positive integer; the RPF satisfies a following condition: 48×nRPF can be exactly divided by 12; t is an integer by which 48×nRPF can be exactly divided; and L≤t. With the present invention, the number of the SRS resources in a LTE-A system can be efficiently increased.