A novel mixed granularity frequency hopping method for single carrier multi-user access system
In this paper, a mixed granularity frequency hopping method for single carrier multi-user access system is introduced. This frequency hopping method solves the problem of mixed bandwidth granularity localized transmission in a single carrier system. The main concept is using the predefined mode to guarantee the orthogonal frequency hopping pattern and single carrier property.
We study the scalability problem of a priori-like algorithms that are used in mining association rules. We show how a priori suffers from performance deterioration for large-scale problems and propose alternative data structures and operations that can be used to apply the a priori-trick optimization method in large-scale problems. In the proposed method, the database is transformed into a more efficient structure that is used along with the intersection operation, to find the frequent itemsets in the database. The performance evaluation shows that, with a minor increase in the storage requirement, the proposed technique outperforms significantly the existing algorithms especially in large-scale problems.