Adaptive Reverse Repetition Control for OFDMA Coverage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In OFDMA systems, the integrated gain from subchannelization and repetition is not always additive, and under certain conditions, repetition can lead to a deterioration of reverse coverage, especially when the terminal moves away from the base station, resulting in reduced power and gain.
Innovation Solution
A method that dynamically determines whether to enable repetition based on maintaining Quality of Service (QoS) and transmission speed, adjusting the number of subchannels, and optimizing repetition times to ensure that the reverse repetition gain exceeds power loss, thereby improving reverse coverage without sacrificing terminal transmission speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If repetition is activated to improve reverse coverage, then reverse gain is improved, but transmit power per subchannel decreases leading to potential gain deterioration
Solution Approach 1:
The patent applies dynamics by making the repetition configuration adjustable and adaptive rather than fixed. The base station dynamically configures repetition parameters (number of repetitions, subchannel allocation) based on terminal feedback and channel conditions. This allows the system to optimize the balance between repetition gain and power per subchannel in real-time, preventing the integrated gain from deteriorating while maintaining improved reverse coverage.
Solution Approach 2:
The patent changes key parameters including the number of repetitions, subchannel allocation, and power distribution to optimize reverse gain. By adjusting these parameters based on terminal feedback and channel conditions, the system can maintain the integrated gain above the threshold required for coverage improvement while managing the transmit power per subchannel effectively.
2Reliability
If subchannelization is used to concentrate power, then reverse gain is improved, but bandwidth utilization is reduced
Solution Approach 1:
The patent applies segmentation by dividing the available bandwidth into multiple subchannels and allowing terminals to selectively occupy different numbers of subchannels based on their reverse gain requirements. This segmented approach enables flexible power concentration on fewer subchannels when needed for coverage, while allowing broader bandwidth utilization when terminals are closer to the base station, thus resolving the contradiction between reverse gain and bandwidth utilization.
Solution Approach 2:
The patent makes subchannel allocation dynamic, allowing terminals to adjust the number of occupied subchannels based on channel conditions and distance from the base station. This dynamic subchannelization enables the system to optimize the trade-off between concentrating power for reverse gain and utilizing broader bandwidth for higher data rates, preventing either extreme from dominating.
3Reliability
If repetition times are increased to improve reverse gain, then reverse coverage is enhanced, but transmission speed decreases
Solution Approach 1:
The patent applies dynamics by making repetition configuration adaptive rather than fixed. The base station configures the number of repetitions based on terminal feedback regarding channel conditions and distance. This dynamic adjustment allows the system to use higher repetition counts for terminals needing coverage extension while maintaining lower repetition counts (faster transmission) for terminals with good channel conditions, thus resolving the contradiction between reverse coverage and transmission speed.
Solution Approach 2:
The patent applies local quality by allowing different repetition configurations for different terminals or different time periods based on local channel conditions. Rather than applying a uniform repetition strategy to all terminals, the system tailors the repetition count to each terminal's specific needs, ensuring that only those requiring coverage enhancement use higher repetition counts, thereby minimizing the impact on overall transmission speed.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method for improving reverse coverage is disclosed, comprising: A, when a base station requests a terminal to enable the reverse repetition, under the condition that the service quality requirement and the transmission speed of the terminal are persistent, then step B is executed; B, if the reverse gain still cannot be improved after repetition, the reverse repetition will not be enabled; or, the reverse repetition will be enabled. The method of the present invention can take account of subchannelization gain, repetition gain and the interaction of both as an integration, to ensure that the whole gain of reverse link increases after the enabled repetition, and to prevent the system from sacrificing the bandwidth without improving but deteriorating the reverse coverage capability in certain circumstances after the enabled repetition occurs.