Adaptive Search Window Placement for CDMA Path Detection
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Solution Overview
Problem
In CDMA or WCDMA wireless communications systems, the existing methods for determining search window placement and size are often inadequate, leading to excessive search time and power consumption due to inefficient window sizing and placement, which is not optimized for handoff performance.
Innovation Solution
An adaptive sub-window based mechanism that configures smaller sub-windows within the search window, using counters and thresholds to accurately determine and adjust the placement and size of the search window, reducing redundant searches and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the search window size is increased to improve handoff performance, then path detection reliability is improved, but search time and power consumption increase
Solution Approach 1:
The patent divides the search window into multiple sub-windows and performs searches in parallel. This segmentation allows the system to cover the same search range as a single large window but with reduced time complexity, as multiple sub-searches can be executed concurrently or in an optimized sequence, thereby maintaining reliability while reducing total search time.
Solution Approach 2:
The patent applies a two-stage search approach: first performing a coarse search with a larger window to quickly identify candidate paths, then performing a refined search with smaller sub-windows only in regions where paths are likely to exist. This partial action approach avoids exhaustive searching of the entire large window, reducing power consumption and search time while maintaining detection reliability.
2Measurement precision
If the search window size is increased to ensure all paths are detected, then measurement precision is improved, but device complexity and power consumption increase
Solution Approach 1:
By segmenting the search window into sub-windows, the patent reduces the complexity of managing a single large window while maintaining comprehensive path detection. Each sub-window can be independently managed and processed, simplifying the overall search mechanism architecture and reducing computational overhead.
Solution Approach 2:
The patent performs a preliminary coarse search before the refined sub-window search to identify regions of interest. This preliminary action provides guidance for subsequent detailed searches, allowing the system to focus computational resources only where needed, thereby reducing overall device complexity and power consumption while maintaining high detection accuracy.
3Reliability
If the search window is fixed and optimized for handoff, then handoff performance is improved, but adaptability to different channel conditions deteriorates
Solution Approach 1:
The patent implements dynamic search window adjustment based on channel conditions. The system can adaptively modify the size, position, and number of sub-windows according to detected channel characteristics such as delay spread and signal strength. This dynamic behavior allows the search mechanism to maintain optimal handoff performance across varying channel conditions while preserving adaptability.
Solution Approach 2:
The patent changes search parameters (window size, sub-window positions, search thresholds) based on detected channel conditions. By monitoring channel characteristics and adjusting search parameters accordingly, the system maintains reliable handoff performance in diverse environments without being constrained by a fixed window configuration.
Data Source
AI summary
A method of path detection in a multi-path communications system that includes selecting an object for configuring a search window, setting at least one sub-window, wherein the sub-window is smaller in size than the search window, providing a first counter for the object, setting a threshold, selecting a decision period for a duration of the object, and detecting a path in a selected region with the at least one sub-window in a plurality of modes corresponding to the threshold.