Sounding Reference Signal Mapping for Beam Selection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In existing LTE/LTE-Advanced systems, there is no defined sounding reference signal (SRS) suitable for beamforming in the uplink, making it difficult to efficiently determine which beam provides good reception quality for user apparatuses.
Innovation Solution
A user apparatus and base station system that transmits and receives identification information for specific uplink and downlink reference signals using multiple antenna ports or beams, allowing for efficient selection of optimal beams for communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If beamforming is applied in the uplink to compensate for propagation loss in high frequency band, then reception quality is improved, but there is no defined sounding reference signal to efficiently determine which beam provides good reception quality
Solution Approach 1:
The patent applies preliminary action by having the user apparatus transmit multiple uplink signals through multiple antenna ports or beams before actual data communication. The base station measures reception quality of these preliminary signals and feeds back identification information, enabling the user apparatus to select optimal beams for subsequent communication without trial-and-error during actual data transmission.
Solution Approach 2:
The patent implements feedback by having the base station transmit identification information of the uplink signal with good reception quality back to the user apparatus. This feedback mechanism enables the user apparatus to efficiently select the optimal beam for data transmission based on measured reception quality, resolving the beam selection difficulty.
2Productivity
If multiple antenna ports or beams are used for uplink transmission, then system capacity is improved, but it becomes complex to determine which beam results in good reception quality among plurality of beams
Solution Approach 1:
The patent applies segmentation by dividing the uplink transmission into multiple independent antenna ports or beams, each carrying a sounding reference signal. The base station measures each segment separately and provides identification information for the best performing segment, simplifying the complexity of determining optimal beams among multiple options.
Solution Approach 2:
The patent uses identification information as an intermediary element that carries feedback about beam performance from the base station to the user apparatus. This intermediary simplifies the complex task of beam determination by providing a direct indicator of which beam performed best, eliminating the need for complex analysis and decision-making at the user apparatus.
3Object-affected harmful factors
If massive MIMO is applied to concentrate electric field strength on small area, then inter-user interference is reduced, but propagation loss in high frequency band increases
Solution Approach 1:
The patent applies dynamics by enabling dynamic beam selection and adjustment in the uplink. The user apparatus can switch between different antenna ports or beams based on real-time reception quality feedback, allowing the system to adapt to changing propagation conditions and compensate for energy loss while maintaining the interference suppression benefits of massive MIMO.
Solution Approach 2:
The patent changes the parameter of transmission directionality by using beamforming with multiple antenna ports. This concentrates the electric field strength in specific directions to reduce inter-user interference while the system compensates for propagation loss through adaptive beam selection and feedback mechanisms, allowing energy-efficient communication in high frequency bands.
Data Source
AI summary
A user apparatus is disclosed herein that includes a receiver configured to receive a plurality of synchronization signals and a transmitter configured to transmit a sounding reference signal associated with a specific synchronization signal of the plurality of synchronization signals. The transmitter also maps the sounding reference signal to consecutive OFDM symbols in one slot.