TD-SCDMA Gain Control Using Time-Slot Power Segmentation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional Automatic Gain Control (AGC) methods in TD-SCDMA communication systems face performance deterioration when reception powers differ significantly among data blocks, failing to effectively converge signals to a target level.

Innovation Solution

A method that determines an average power in a measurement section of a time slot, calculates an average error power from a difference between a target power and the average power, and adjusts the output power by adding the average error power to the received power, ensuring signal convergence to a target level.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional AGC methods are used to control gain in TD-SCDMA, then the system can operate with multiple subscribers on a single frequency, but performance deteriorates when reception powers differ significantly among data blocks

Engineering Contradiction:

Improveability to handle multiple subscribers on single frequencyVSAvoidsignal convergence performance

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent divides the time slot into multiple measurement sections (first measurement section before midamble, second measurement section after midamble) and performs separate gain calculations for each section. This segmentation allows the system to handle different reception power conditions in different parts of the time slot, improving reliability when power differences exist among data blocks while maintaining the ability to serve multiple subscribers.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent performs gain estimation and control in the first measurement section before the midamble is processed, establishing a preliminary gain value. This preliminary action ensures that when data blocks with varying reception powers are received, the gain is already optimized, preventing performance deterioration before the actual data processing occurs.

Inventive Principle:

Principle #10Preliminary action

2Device complexity

If gain is fixed after N iterations using Data-1, then the AGC process is simplified, but the signal may not converge to target level when reception power differences are high

Engineering Contradiction:

ImproveAGC process complexityVSAvoidsignal level convergence accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

Instead of fixing gain after a predetermined number of iterations, the patent continuously performs gain estimation and control in both the first and second measurement sections of each time slot. This continuous action ensures that gain is consistently optimized for each data block regardless of reception power variations, achieving precise signal level convergence without excessive complexity.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The patent implements a feedback mechanism where the receiver measures reception power in each measurement section, compares it with the target level, and adjusts the gain accordingly. This feedback loop operates in both measurement sections, ensuring that even when reception power differences are high, the signal converges to the target level with high precision.

Inventive Principle:

Principle #23Feedback

3Speed

If AGC loop speed is increased based on error value, then convergence speed improves, but stability may be compromised when error fluctuates

Engineering Contradiction:

ImproveAGC convergence speedVSAvoidgain control stability

Core Design Contradiction:

SpeedVSStability of the object's composition

Solution Approach 1:

The patent segments the AGC process into two distinct measurement sections with separate gain calculations. In the first measurement section, gain is estimated with initial convergence speed. In the second measurement section, gain is refined with stability-focused adjustment. This segmentation allows the system to achieve both fast convergence and stable gain control, avoiding the trade-off between speed and stability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent dynamically adjusts the AGC loop behavior based on the measurement section. In the first measurement section, the loop operates with faster convergence characteristics. In the second measurement section, it transitions to a more stable, refined adjustment mode. This dynamic adaptation allows the system to optimize both convergence speed and stability at different stages of the processing.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS9548772B2Apparatus and method for controlling gain in communication system

Publication Date: 2017.01.17 SAMSUNG ELECTRONICS CO LTD

AI summary

A method and a terminal are provided for use in a communication system. The method includes determining an average power from power obtained in a measurement section of a data symbol in a time slot including an updated gain section and a maintained gain section, the measurement section starting after a last gain is applied in the data symbol and ending before a mid-amble of the time slot is buffered, determining an average error power from a difference between a predetermined target power and the average power, and determining an output power by adding the average error power to power that is received over the time slot.