Wireless Relay Device SRS Transmission Timing
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Solution Overview
Problem
In wireless relay systems using high frequency radio bands, the need to maintain orthogonality in PUCCH and PUSCH formats is compromised due to guard period requirements, leading to inefficiencies in resource utilization, particularly in scenarios where the relay station cannot transmit SRS on SC-FDMA symbol #13 or allocate SRS to mobile stations effectively.
Innovation Solution
A wireless relay device and method that shifts the reception timing of the access link subframe relative to the backhaul subframe, allowing for the use of SC-FDMA symbol #13 as a 'fake' symbol for SRS transmission, enabling efficient switching between transmission and reception modes while maintaining resource orthogonality and allowing SRS transmission only when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a guard period is provided for switching RF circuit between transmission and reception in TD relay, then the relay station can switch between transmission and reception modes, but resource utilization efficiency deteriorates due to loss of SC-FDMA symbol #13 for SRS transmission
Solution Approach 1:
The relay station determines in advance whether to transmit SRS in the subframe immediately before the backhaul subframe, and based on this determination, configures whether to treat SC-FDMA symbol #13 as a fake symbol. This preliminary determination allows the system to optimize resource utilization before the actual transmission occurs, resolving the contradiction between needing guard periods for switching and maintaining resource efficiency.
Solution Approach 2:
The patent introduces dynamic configuration of the 'fake symbol' based on SRS transmission needs. The SC-FDMA symbol #13 is configured as a fake symbol only when SRS is not transmitted in the previous subframe, allowing the system to adaptively switch between using the symbol for data transmission and for SRS transmission, thereby resolving the contradiction between switching capability and resource efficiency.
2Productivity
If SC-FDMA symbol #13 is used for data transmission in access link subframe, then resource utilization is maximized, but SRS transmission capability is lost when it is needed for channel quality measurement
Solution Approach 1:
The system performs preliminary determination of SRS transmission needs before configuring the access link subframe. Based on this advance determination, the relay station decides whether to configure SC-FDMA symbol #13 as a fake symbol or use it for data transmission, ensuring both resource efficiency and SRS transmission capability are maintained when needed.
Solution Approach 2:
The patent changes the configuration parameter of SC-FDMA symbol #13 dynamically - it can be configured as either a fake symbol (for SRS transmission) or a data transmission symbol based on the SRS transmission needs. This parameter change allows the system to adapt between maximizing resource utilization and maintaining SRS transmission flexibility.
3Reliability
If the relay station transmits SRS in every subframe, then channel quality measurement is continuously maintained, but resource waste occurs due to unnecessary SRS transmissions
Solution Approach 1:
The relay station performs preliminary determination of whether SRS transmission is actually needed in the subframe before the backhaul subframe. Based on this determination, it configures the fake symbol accordingly. This prevents unnecessary SRS transmissions while maintaining channel quality measurement accuracy when needed, resolving the contradiction between reliability and energy efficiency.
Solution Approach 2:
Instead of transmitting SRS in every subframe (excessive action), the system transmits SRS only in subframes where it is actually needed (partial action). The preliminary determination mechanism identifies these necessary instances, reducing energy waste from unnecessary transmissions while maintaining sufficient channel quality measurement accuracy.
Data Source
AI summary
In a wireless relay method for relaying a signal between a base station and a mobile station, if an SRS is transmitted in a subframe immediately previous to the backhaul subframe, the last symbol of an access link subframe is set as a fake symbol in which the SRS that the mobile station transmits to the wireless relay device is not configured. The signal transmitted from the mobile station to the wireless relay device in a previous symbol of one of the fake symbol is received, and switched to transmission from the wireless relay device to the base station. If the SRS is not transmitted in a subframe immediately previous to the backhaul subframe, the signal transmitted from the mobile station to the wireless relay device is received in the last symbol of the access link subframe, and switched to transmission from the wireless relay device to the base station.