Implementing a Flexible Testbed Using Dynamic FFR Scheme in OFDMA Based Cognitive Radio Networks

10.36227/techrxiv.13710202.v1 ◽

2021 ◽

Author(s):

Joydev Ghosh

Keyword(s):

Cognitive Radio ◽

Multiple Access ◽

Network Performance ◽

Carrier Frequency Offset ◽

Analytical Framework ◽

Radio Networks ◽

Superior Performance ◽

Frequency Division ◽

Performance Parameters ◽

Frequency Reuse Factor

<div>In this paper, the femtocell resource allocation in the Orthogonal Frequency Division Multiple Access (OFDMA) integrated cognitive radio (CR) networks has been demonstrated to optimize the network performance, while reducing the outage users at cell edges. The sub-band sharing flexibility not only improves the spectral efficiency of the dynamic FFR scheme against conventional approach but also it alleviates outage probability and further noticeable amount of improvement can be found in superior performance parameters such as capacity, CDF of SINR and overall cell throughput. We yield an analytical framework to ascertain the orthogonality of the subcarriers by compensating carrier frequency offset (CFO) to ensure better OFDMA performance in the proposed network model and illustrates the influence of frequency reuse factor (FRF) at cell edges via simulation results. </div>

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Performance Analysis of the IEEE 802.11ax MAC Protocol for Heterogeneous Wi-Fi Networks in Non-Saturated Conditions

Sensors ◽

10.3390/s19071540 ◽

2019 ◽

Vol 19 (7) ◽

pp. 1540 ◽

Cited By ~ 4

Author(s):

Kyu-haeng Lee

Keyword(s):

Performance Analysis ◽

Multiple Access ◽

Network Performance ◽

Mac Protocol ◽

Analytical Framework ◽

Frequency Division ◽

Delay Performance ◽

Traffic Conditions ◽

Ieee 802.11Ax ◽

Proposed Model

The IEEE 802.11ax standard, which realizes multi-user transmission based on orthogonal frequency division multiple access (OFDMA), has been highlighted as a key technology to meet high future demand for Wi-Fi systems. Since this standard is still being developed, performance analysis through mathematical modeling is of paramount importance; however, existing studies have several limitations. Firstly, most of these consider only the saturation network throughput, whereas for 802.11ax in particular, the access delay of the nodes needs to be studied carefully, since they no longer acquire the medium independently but depend solely on the access point’s (AP’s) schedule. Secondly, since the network performance may be affected to a greater extent by legacy nodes than by 802.11ax nodes, it is desirable to consider various heterogeneous cases of networks with existing legacy nodes. In this paper, a new analytical framework for the 802.11ax MAC protocol is provided. Markov-chain-based models are developed to represent the behavior of the 802.11ax nodes, and both non-saturated traffic conditions and co-existence with the legacy nodes are considered. Through both analysis and MATLAB simulations, it is shown that the proposed model accurately evaluates the throughput and the delay performance under various network conditions.

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