Mobile Station TPC Command Selection for Uplink Quality
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional uplink transmission power control methods during soft handover do not adequately consider the propagation environment, leading to suboptimal transmission quality and increased retransmissions.
Innovation Solution
A mobile station apparatus that receives and prioritizes transmission power control commands based on acknowledgement responses from multiple base stations, selecting the command that reflects the most recent and favorable uplink propagation environment to control transmission power effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the mobile station apparatus receives TPC commands from multiple base station apparatuses during soft handover, then the transmission power control can be performed, but the TPC commands may conflict due to different propagation environments leading to suboptimal transmission quality
Solution Approach 1:
The patent uses ACK/NACK feedback from the base station apparatus to determine which TPC command to select. The mobile station apparatus monitors the ACK/NACK status and selects TPC commands from base stations that have successfully received uplink packets (ACK state), thereby ensuring that the selected TPC command reflects the actual favorable propagation environment and resolves command conflicts
Solution Approach 2:
The patent changes the selection criterion from static (e.g., always selecting the strongest signal) to dynamic based on transmission quality feedback. By using ACK/NACK status as a variable parameter, the system adapts the TPC command selection to current propagation conditions, improving transmission quality while managing complexity through a clear selection rule
2Ease of operation
If the mobile station apparatus selects TPC commands based on downlink link quality only, then the selection process is simplified, but the uplink propagation environment is not adequately considered leading to increased retransmissions
Solution Approach 1:
The patent introduces uplink transmission quality feedback through ACK/NACK responses from the base station. Instead of relying solely on downlink measurements, the system uses actual uplink packet reception status to guide TPC command selection, ensuring that the selected command reflects real uplink propagation conditions and reduces retransmissions
Solution Approach 2:
The ACK/NACK signal acts as an intermediary that bridges the gap between downlink measurements and uplink transmission quality. By using this intermediary feedback mechanism, the system can make informed TPC command selections that account for uplink conditions without requiring complex direct uplink measurements at the mobile station
Data Source
AI summary
A mobile station device for selecting a TPC command to improve the transmission quality of a packet in an upstream circuit more reliably, so that it reduces the re-transmission in the upstream circuit to improve a sector throughput. In this mobile station device, a demodulate unit (210) outputs a received signal of each base station device to an error correction decode unit (220) and a TPC command select unit (240). The error correction decode unit (220) outputs an ACK/NACK of each base station device to a data re-transmission control unit (230) and the TPC command select unit (240). The TPC command select unit (240) selects the TPC command of the highest priority on the basis of the information of the ACK/NACK. A transmission power control unit (280) determines the transmission power according to the contents of the TPC command of the highest priority. Moreover, the transmission power control unit (280) determines the transmission power by an or-of-down method, in case a plurality of TPC commands of the highest priority are outputted from the TPC command select unit (240).