Uplink Resource Allocation in Carrier Aggregation SRS Subframes
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Solution Overview
Problem
In wireless communication systems, particularly in carrier aggregation systems, there is a need for efficient transmission methods that balance the transmission of sounding reference signals (SRS) and uplink data to maintain channel estimation accuracy and ensure reliable data transmission, while also maintaining the single carrier property of SRS transmission.
Innovation Solution
The proposed method involves allocating the SRS and PUSCH resources such that the SRS is transmitted in a reserved SC-FDMA symbol, with the PUSCH being transmitted in the remaining symbols, and optionally applying rate matching or puncturing to ensure the SRS maintains its single carrier characteristics and maximizes transmit power, or prioritizing the SRS or PUSCH allocation based on specific conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If SRS and PUSCH are transmitted simultaneously in the same subframe in a carrier aggregation system, then data transmission efficiency is improved, but the single carrier property of SRS transmission is compromised and channel estimation accuracy deteriorates
Solution Approach 1:
The patent segments the subframe into different symbol types (first SC-FDMA symbols for PUSCH, second SC-FDMA symbols for SRS). By separating the transmission resources in the time domain at the symbol level, the system allows simultaneous transmission of PUSCH and SRS while maintaining the single carrier property of SRS in its dedicated symbols, thus resolving the contradiction between data transmission efficiency and channel estimation accuracy.
2Measurement precision
If SRS transmission power is maximized to improve channel estimation accuracy, then channel estimation performance is improved, but data transmission throughput is reduced
Solution Approach 1:
The patent applies different transmission characteristics to different parts of the subframe. In the second SC-FDMA symbols allocated for SRS, the system maximizes transmission power and maintains single carrier property to ensure high channel estimation accuracy. In the first SC-FDMA symbols for PUSCH, normal data transmission parameters are used to maintain throughput. This local differentiation resolves the contradiction between channel estimation accuracy and data transmission throughput.
Data Source
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AI summary
A data transmission method and device are provided in a wireless communication system. A user equipment transmits uplink data using a first physical uplink shared channel (PUSCH) resource, allocated to a first component carrier (CC) among a plurality of CC's, in a sounding reference signal (SRS) subframe. The plurality of CC's in said SRS subframe includes a single carrier-frequency division multiple access (SRS SC-FDMA) symbol, which is reserved for transmitting SRS.