Format-Based Power Control for Wireless Convergence
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Solution Overview
Problem
Existing power control mechanisms in wireless communication systems, particularly those using CDMA technologies, experience slow convergence of signal quality targets when switching between different transport formats, leading to inefficiencies in achieving data error rate targets due to gradual adjustments over multiple transmission time intervals.
Innovation Solution
The implementation of an outer-loop power control circuit with baseline control circuits and a target biasing circuit that maintains a common baseline signal quality target for all transport formats, adjusted per transmission interval, and applies format-specific offsets to quickly adapt to changes in signal propagation and transport format use, enabling rapid convergence to the required signal quality targets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the outer-loop significantly increases the signal quality target when erroneous data is received (jump algorithm), then the convergence time is faster, but the average data error rate becomes biased because correct data is received more often than erroneous data
Solution Approach 1:
The patent changes the parameter of signal quality target adjustment by introducing transport format-specific offsets to the baseline signal quality target. This allows the system to quickly adapt to different transport formats while maintaining an unbiased average data error rate through the baseline target that is adjusted slightly for correct data reception.
Solution Approach 2:
The patent segments the signal quality target into two components: a baseline signal quality target that is common to all transport formats and is adjusted slightly for correct data reception, and transport format-specific offsets that provide additional adjustment when needed. This segmentation resolves the contradiction by allowing fast convergence through offsets while maintaining reliability through the baseline target.
2Reliability
If the outer-loop maintains separate signal quality targets for each transport format, then the data error rate target can be achieved for each format, but the convergence is slow when switching between transport formats because the targets must be adjusted over multiple transmission time intervals
Solution Approach 1:
The patent applies transport format-specific offsets to the baseline signal quality target in advance, allowing the system to quickly converge to the appropriate signal quality target when switching between transport formats. This preliminary action through offset application eliminates the need for gradual adjustment over multiple transmission time intervals.
Solution Approach 2:
The baseline signal quality target serves as a universal foundation for all transport formats, while transport format-specific offsets provide format-specific adjustments. This multi-functional approach allows a single baseline target to serve all formats while maintaining the ability to achieve data error rate targets for each individual format through the offsets.
3Reliability
If the outer-loop adjusts the signal quality target over multiple transmission time intervals to account for changing signal propagation conditions, then the target converges to the correct value, but the convergence process is slow and inefficient
Solution Approach 1:
The patent introduces transport format-specific offsets as a parameter change that allows the signal quality target to quickly adapt to different transport formats and signal propagation conditions. This parameter change enables fast convergence by applying the appropriate offset immediately when a transport format is detected, rather than gradually adjusting the target over multiple transmission time intervals.
Data Source
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AI summary
Power control methods and apparatus taught herein advantageously provide quick convergence to the signal quality target needed to achieve a given data error rate target, when changes in transport format use by a given transport channel require such convergence. Specifically, the methods and apparatus maintain a "baseline" signal quality target that stays current with changing signal propagation conditions because it is common to all transport formats used by the transport channel. The methods and apparatus then bias this baseline signal quality target with a target offset particularized for the transport format in use. This offset may be selected from memory or dynamically calculated, and, regardless, can often be applied after a single transmission time interval.