Uplink SRS Bandwidth Adjustment for Power-Limited TDD UEs
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Solution Overview
Problem
In LTE TDD systems, transmitting SRS with the largest bandwidth in the UpPTS time slot leads to power limitations in unfavorable channel environments, resulting in a lower signal-to-noise ratio and poor channel information detection capabilities for UE.
Innovation Solution
The method involves determining whether SRS is transmitted with the UpPTS and adjusting the bandwidth to a non-extensive level to avoid power limits, using signaling indications to preset specific SRS bandwidth configurations, allowing accurate channel information detection while maintaining a suitable signal-to-noise ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If SRS is transmitted with the largest bandwidth in UpPTS time slot, then the bandwidth coverage is maximized, but the signal-to-noise ratio deteriorates due to power limit
Solution Approach 1:
The patent applies dynamics by making the SRS bandwidth adjustable rather than fixed. The base station dynamically configures the SRS bandwidth level through signaling, allowing the system to adapt the bandwidth according to channel conditions and power availability. This resolves the contradiction by enabling the system to switch between large bandwidth (for good channel conditions) and smaller bandwidth (for unfavorable conditions where power limits would degrade SNR).
Solution Approach 2:
The patent changes the bandwidth parameter of SRS transmission based on detected power limits. When the base station detects that a UE has reached its power limit, it adjusts the SRS bandwidth level parameter through signaling. This parameter change allows the system to maintain adequate signal-to-noise ratio by reducing bandwidth when power is constrained, while still supporting wideband measurements when power is sufficient.
2Area of stationary object
If SRS bandwidth is extended to the full uplink system bandwidth in UpPTS, then the channel measurement coverage is improved, but the power consumption increases causing power limit
Solution Approach 1:
The system dynamically adjusts SRS bandwidth based on power availability. The base station monitors whether UEs reach their power limits and responds by configuring appropriate bandwidth levels through signaling. This dynamic adjustment allows the system to maximize bandwidth utilization when power is sufficient while reducing bandwidth (and thus power consumption) when UEs hit their power limits.
Solution Approach 2:
The patent changes the SRS bandwidth parameter in response to power limit conditions. By adjusting this parameter through base station signaling, the system can control the trade-off between bandwidth coverage and power consumption. When power limits are detected, the bandwidth parameter is reduced accordingly, preventing excessive power consumption while maintaining measurement capability.
3Adaptability or versatility
If SRS is transmitted with extended bandwidth in UpPTS, then the downlink channel measurement capability is enhanced, but the signal-to-noise ratio decreases due to power distribution
Solution Approach 1:
The system dynamically adapts SRS bandwidth based on channel conditions and power availability. The base station detects power limits and adjusts the bandwidth configuration accordingly through signaling. This dynamic behavior allows the system to maintain high measurement precision by using smaller bandwidth when power is limited (preserving SNR) while enabling wideband measurements when power is sufficient (enhancing adaptability).
Solution Approach 2:
The patent adjusts the SRS bandwidth parameter to optimize the balance between measurement capability and signal-to-noise ratio. By changing this parameter based on detected power conditions, the system ensures that measurements are performed with adequate SNR when power is constrained, while still supporting enhanced measurement capabilities when power is sufficient.
Data Source
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AI summary
The present invention discloses a method, system and device for determining a bandwidth of an uplink sounding reference signal SRS. The method for determining the bandwidth of the uplink SRS comprises the following steps: determining whether SRS is transmitted with the uplink pilot time slot if the SRS is transmitted with the largest bandwidth level; transmitting SRS with the non-extensive SRS bandwidth if SRS is determined to be transmitted with the uplink pilot time slot and the UE reaches the power limit. In the present invention, the signal-to-noise ratio detected on the bandwidth with which SRS transmitted can be maintained, and the accurate detection of the channel information is thereby realized.