Dynamic Antenna Switch Pitch Control for LTE Uplink Diversity
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Solution Overview
Problem
The CL-ASTD scheme in LTE systems lacks specific arrangements for base and user apparatuses, leading to reduced accuracy in scheduling and increased antenna switches due to periodic transmission of sounding reference signals, which affects communication quality, especially in cases of short fading pitches and frequent antenna switches.
Innovation Solution
A base station apparatus and user apparatus with a reference signal measurement unit, switch pitch determination unit, and transmitting unit to dynamically determine and transmit the antenna switch pitch for transmitting reference signals based on receive levels, allowing proper control of antenna switches in mobile communication systems with transmit diversity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the user apparatus transmits sounding reference signals periodically from each antenna to enable CL-ASTD switching, then the base station can measure CQI and select the optimal antenna for data transmission, but the scheduling accuracy is reduced and the number of antenna switches increases, affecting communication quality
Solution Approach 1:
The patent applies dynamics by making the antenna switch pitch configurable and adaptable rather than fixed. The base station can dynamically adjust the switch pitch based on channel conditions, user mobility, and quality requirements. This allows the system to optimize between measurement accuracy and communication quality in real-time, resolving the contradiction by making the switching behavior adaptive to current system needs.
Solution Approach 2:
The patent changes the parameter of antenna switch pitch from a fixed periodic value to a configurable parameter that can be adjusted based on system conditions. By modifying this parameter, the system can balance between transmitting enough reference signals for accurate scheduling while avoiding excessive antenna switches that degrade communication quality. The configurable pitch allows optimization of the trade-off between measurement precision and reliability.
2Measurement precision
If the antenna switch pitch is shortened to increase the number of reference signal transmissions for better scheduling accuracy, then the scheduling accuracy improves, but the number of antenna switches increases which reduces communication quality
Solution Approach 1:
The system dynamically adjusts the antenna switch pitch based on current channel conditions and quality requirements. When channel conditions are good or user mobility is low, the pitch can be shortened to improve scheduling accuracy. When conditions deteriorate or mobility increases, the pitch is lengthened to maintain communication quality. This dynamic adaptation resolves the contradiction by allowing the system to optimize the trade-off in real-time.
Solution Approach 2:
The patent introduces configurable antenna switch pitch as a adjustable parameter that can be optimized based on system conditions. By changing this parameter, the system can control the frequency of reference signal transmissions and antenna switches. The ability to modify this parameter allows the system to achieve better scheduling accuracy when needed while limiting the negative impact on communication quality, thus resolving the contradiction between these two opposing requirements.
3Reliability
If the antenna switch pitch is lengthened to reduce the number of antenna switches and improve communication quality, then the communication quality improves, but the scheduling accuracy is reduced due to fewer reference signal transmissions
Solution Approach 1:
The system uses dynamic adjustment of antenna switch pitch to respond to changing conditions. When communication quality is poor or user mobility is high, the pitch is shortened to increase reference signal transmissions and improve scheduling accuracy. When quality is good and conditions are stable, the pitch is lengthened to reduce unnecessary switching. This dynamic behavior allows the system to maintain an optimal balance between the two contradictory requirements.
Solution Approach 2:
The configurable antenna switch pitch parameter enables the system to adjust the frequency of reference signal transmissions based on system needs. By optimizing this parameter, the system can ensure sufficient measurements for scheduling accuracy while avoiding excessive antenna switches that would degrade communication quality. The parameter adjustment capability resolves the contradiction by allowing flexible optimization of the trade-off between these two performance metrics.
4Productivity
If transmit diversity is applied using a single RF circuit with antenna switching, then the system achieves improved throughput and coverage for high-capacity user equipment, but requires complex switching control and periodic reference signal transmission which consumes resources
Solution Approach 1:
The patent applies dynamics by implementing configurable and adaptable antenna switching control rather than fixed complex switching. The switch pitch can be dynamically adjusted based on channel conditions, user requirements, and system load. This dynamic control simplifies the switching logic by making it adaptive to current conditions, reducing the overall complexity while maintaining the throughput benefits of transmit diversity.
Solution Approach 2:
The introduction of configurable antenna switch pitch as a controllable parameter allows the system to optimize the switching behavior. By adjusting this parameter, the system can reduce unnecessary antenna switches and reference signal transmissions, thereby reducing control complexity and resource consumption while maintaining the essential transmit diversity functionality for improved throughput. The parameter optimization resolves the contradiction between productivity gain and complexity increase.
Data Source
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AI summary
A base station apparatus in a radio communication system where transmit diversity is applied in uplinks includes a reference signal measurement unit configured to measure a receive level of the reference signal, a switch pitch determination unit configured to determine the antenna switch pitch of transmitting the reference signal based on the receive level measured by the reference signal measurement unit, and a transmitting unit configured to transmit the antenna switch pitch determined by the switch pitch determination unit.