Cooperative Spectrum Sensing with Spatial Weighting
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Solution Overview
Problem
Current cooperative spectrum sensing methods in cognitive radio systems face challenges in accurately distinguishing between licensed and non-licensed spectrum usage, leading to missed spectrum opportunities due to improper partner user selection and interference from non-target primary users, especially when the transmission range of primary users is comparable to or smaller than that of cognitive radio users.
Innovation Solution
The system employs a communication-oriented cooperative spectrum sensing approach, where cognitive radio users coordinate with partner users to share spectrum sensing information, weighting it based on proximity and using optimal decision thresholds to improve detection performance, thereby enhancing the accuracy of spectrum opportunity identification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If cooperative spectrum sensing is performed with multiple partner users, then detection performance is improved, but false alarms increase due to interference from non-target primary users
Solution Approach 1:
The patent applies local quality by making the sensing process location-aware. Each cognitive radio user weights the sensing information from partner users based on their relative positions. Users closer to the fusion user contribute more heavily to the decision, while distant users contribute less. This spatially differentiated weighting resolves the contradiction by incorporating local spatial information to distinguish between relevant and irrelevant primary user signals, thereby maintaining high detection accuracy while reducing false alarms from distant non-target primary users.
2Measurement precision
If spectrum sensing information from all partner users is combined equally, then comprehensive spectrum coverage is achieved, but irrelevant information from distant users degrades detection accuracy
Solution Approach 1:
The patent implements local quality by assigning different weights to sensing information from different partner users based on their spatial locations. Instead of treating all partner users equally, the system evaluates the relevance of each user's sensing information according to their distance from the fusion user. This ensures that locally relevant information from nearby users has greater impact on the spectrum opportunity decision, while distant users contribute proportionally less, thereby maintaining high detection accuracy without losing critical local information.
Solution Approach 2:
The patent applies parameter changes by dynamically adjusting the weighting parameter based on the spatial configuration of partner users. The weight assigned to each partner user's sensing information is not fixed but varies according to their relative position to the fusion user. This parameter adaptation allows the system to optimize the contribution of each user's information, ensuring that the most relevant local information has the greatest influence on spectrum opportunity identification while filtering out less relevant distant information.
3Productivity
If the transmission range of primary users is small, then spectrum opportunities are more frequent, but distinguishing between licensed and non-licensed usage becomes more difficult
Solution Approach 1:
The patent applies merging by combining sensing information from multiple partner users at a fusion user. When primary users have small transmission ranges, individual users may miss spectrum opportunities or misinterpret the spectrum state. By merging the sensing results from multiple spatially distributed partner users, the system creates a more comprehensive view of the spectrum environment. This collective sensing approach maintains high accuracy in distinguishing licensed from non-licensed usage even when individual primary user transmissions are localized and infrequent.
Data Source
AI summary
A system and method for cooperative spectrum sensing in cognitive radio (CR) systems is provided. A method for CR user operation includes coordinating with partner CR users to share spectrum sensing information, combining spectrum sensing information from partner CR users, and determining if a transmission opportunity exists based on the combined spectrum sensing information. The method also includes transmitting a message to a CR user if the transmission opportunity exists, and storing the message if the transmission opportunity does not exist.