scholarly journals Adaptive Subcarrier Allocation for Orthogonal Frequency Code Division Multiplexing (OFCDM)

2021 ◽  
Author(s):  
Ryan B. Caldwell
Keyword(s):  
Performance Improvement ◽  
Subcarrier Allocation ◽  
Allocation Algorithm ◽  
Frequency Code ◽  
Allocation Process ◽  
Noise Ratio ◽  
Code Division Multiplexing ◽  
A Performance

In this thesis, a novel adaptive subcarrier allocation algorithm is developed for OFCDM. This algorithm utilizes groups of evenly spaced, non-contiguous subcarriers throughout the spectrum. The users are allocated to subcarriers groups with the intention of minimizing the overall BER. This is accomplished by assigning a user to the set of subcarriers that provides the best Signal to Interfenence and Noise Ratio (SINR), while producing the least amount of interference to other users accessing the same subcarrier group. The expected interference produced by this user is then utilized to recalculate the SINR for the subcarrier goup, and the allocation process continues recursively until all users are assigned to subcarriers. The proposed alogrithm is shown to provide a performance improvement ranging from 1.5dB with 2x16 spreading, 7dB with 16x2 spreading. The algorithm is also shown to maintain or improve the BER floor for each OFCDM spreading configuration.

scholarly journals Adaptive Subcarrier Allocation for Orthogonal Frequency Code Division Multiplexing (OFCDM)

2021 ◽  
Author(s):  
Ryan B. Caldwell
Keyword(s):  
Performance Improvement ◽  
Subcarrier Allocation ◽  
Allocation Algorithm ◽  
Frequency Code ◽  
Allocation Process ◽  
Noise Ratio ◽  
Code Division Multiplexing ◽  
A Performance

In this thesis, a novel adaptive subcarrier allocation algorithm is developed for OFCDM. This algorithm utilizes groups of evenly spaced, non-contiguous subcarriers throughout the spectrum. The users are allocated to subcarriers groups with the intention of minimizing the overall BER. This is accomplished by assigning a user to the set of subcarriers that provides the best Signal to Interfenence and Noise Ratio (SINR), while producing the least amount of interference to other users accessing the same subcarrier group. The expected interference produced by this user is then utilized to recalculate the SINR for the subcarrier goup, and the allocation process continues recursively until all users are assigned to subcarriers. The proposed alogrithm is shown to provide a performance improvement ranging from 1.5dB with 2x16 spreading, 7dB with 16x2 spreading. The algorithm is also shown to maintain or improve the BER floor for each OFCDM spreading configuration.

Dynamic Subcarrier and Power Allocation Based on Nash Bargaining Solution in Symmetric Cooperative OFDMA Networks

2011 ◽  
Vol 187 ◽  
pp. 510-515
Author(s):  
Wei Liu ◽  
Jing Min Tang
Keyword(s):  
Power Allocation ◽  
Nash Bargaining Solution ◽  
Nash Bargaining ◽  
Bargaining Solution ◽  
Subcarrier Allocation ◽  
Allocation Scheme ◽  
Allocation Algorithm ◽  
Cooperative Scheme ◽  
Joint Resource Allocation ◽  
Adaptive Power

In this paper, subcarrier and power allocation are jointly considered in a three-node symmetric cooperation orthogonal frequency-division multiple access uplink system. With the help of Nash bargaining solution, the dynamic subcarrier allocation scheme and the adaptive power allocation scheme are proposed for joint optimization. The joint resource allocation is decomposed and solved by dynamic subcarrier allocation algorithm and adaptive power allocation algorithm. Simulation results show the effectiveness of the proposed cooperative scheme.

scholarly journals Computer Data Storage and Management Platform Based on Big Data

2021 ◽  
Vol 2066 (1) ◽  
pp. 012022
Author(s):  
Cheng Luo
Keyword(s):  
Big Data ◽  
Data Management ◽  
Performance Improvement ◽  
Data Storage ◽  
Nonvolatile Memory ◽  
Linear Structure ◽  
Ring Structure ◽  
Computer Data ◽  
Management Platform ◽  
A Performance

Abstract Due to the continuous development of information technology, data has increasingly become the core of the daily operation of enterprises and institutions, the main basis for decision-making development. At the same time, due to the development of network, the storage and management of computer data has attracted more and more attention. Aiming at the common problems of computer data storage and management in practical work, this paper analyzes the object and content of data management, investigates the situation of computer data storage and management in China in recent two years, and interviews and tests the data of programming in this design platform. At the same time, in view of the related problems, the research results are applied to practice. On the basis of big data, the storage and management platform is designed. The research and design adopts a special B+ tree node linear structure of CIRC tree, and the linear node structure is changed into a ring structure, which greatly reduces the number of data persistence instructions and the performance overhead. The results show that compared with the most advanced B+ tree design for nonvolatile memory, crab tree has 3.1 times and 2.5 times performance improvement in reading and writing, respectively. Compared with the previous NV tree designed for nonvolatile memory, it has a performance improvement of 1.5 times, and a performance improvement of 8.4 times compared with the latest fast-fair. In the later stage, the expansion of the platform functions is conducive to the analysis and construction of data related storage and management functions, and further improve the ability of data management.

scholarly journals Multi-Band Spectrum Allocation Algorithm Based on First-Price Sealed Auction

2017 ◽  
Vol 17 (1) ◽  
pp. 104-112 ◽  
Author(s):  
Zijuan Shi ◽  
Gaofeng Luo
Keyword(s):  
Wireless Networks ◽  
Wireless Network ◽  
Economic Efficiency ◽  
Low Complexity ◽  
Spectrum Allocation ◽  
Band Spectrum ◽  
Auction Mechanism ◽  
Allocation Algorithm ◽  
Cognitive Wireless Networks ◽  
Allocation Process

Abstract Auction is often applied in cognitive wireless networks due to its fairness properties and efficiency. To solve the allocation issues of cognitive wireless network inamulti-band spectrum, multi-item auction mechanism and models were discussed in depth. Multi-item highest price sealed auction was designed for cognitive wireless networks’multi-band spectrum allocation algorithm. This algorithm divided the spectrum allocation process into several stages which was along with low complexity. Experiments show that the algorithm improves the utilization of spectrum frequency, because it takes into account the spectrum owner’s economic efficiency and the users’equity.

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