### Abstract

This paper considers the problem of optimal subcarrier allocation in OFDMA systems to achieve the minimum outage probability while guaranteeing fairness. The optimal subcarrier allocation algorithm and the maximum frequency diversity gain are both analyzed through the maximum matching method based on the random bipartite graph theory. Accordingly, a surprising result is found, which shows that the maximum frequency diversity gain in subcarrier-sharing OFDMA systems is the same as that in point-to-point OFDM systems that serve only one user by using N subcarriers. It is then demonstrated that this maximum frequency diversity gain can be achieved by a proposed Random Vertex Rotation based Hopcroft-Karp (RVRHK) algorithm with the time complexity of O(N^{2.5}), where N is the number of subcarriers. Because the theoretical analysis and the RVRHK algorithm are both based on the maximum matching method, the maximum frequency diversity in OFDMA systems is referred to as the max-matching diversity in this paper.

Original language | English |
---|---|

Article number | 5439319 |

Pages (from-to) | 1161-1171 |

Number of pages | 11 |

Journal | IEEE Transactions on Communications |

Volume | 58 |

Issue number | 4 |

DOIs | |

Publication status | Published - Apr 2010 |

Externally published | Yes |

### Fingerprint

### Keywords

- Frequency diversity
- Maximum matching
- OFDMA
- Outage
- Random bipartite graph

### ASJC Scopus subject areas

- Electrical and Electronic Engineering

### Cite this

*IEEE Transactions on Communications*,

*58*(4), 1161-1171. [5439319]. https://doi.org/10.1109/TCOMM.2010.04.080478

**Max-matching diversity in OFDMA systems.** / Bai, Bo; Chen, Wei; Cao, Zhigang; Letaief, Khaled.

Research output: Contribution to journal › Article

*IEEE Transactions on Communications*, vol. 58, no. 4, 5439319, pp. 1161-1171. https://doi.org/10.1109/TCOMM.2010.04.080478

}

TY - JOUR

T1 - Max-matching diversity in OFDMA systems

AU - Bai, Bo

AU - Chen, Wei

AU - Cao, Zhigang

AU - Letaief, Khaled

PY - 2010/4

Y1 - 2010/4

N2 - This paper considers the problem of optimal subcarrier allocation in OFDMA systems to achieve the minimum outage probability while guaranteeing fairness. The optimal subcarrier allocation algorithm and the maximum frequency diversity gain are both analyzed through the maximum matching method based on the random bipartite graph theory. Accordingly, a surprising result is found, which shows that the maximum frequency diversity gain in subcarrier-sharing OFDMA systems is the same as that in point-to-point OFDM systems that serve only one user by using N subcarriers. It is then demonstrated that this maximum frequency diversity gain can be achieved by a proposed Random Vertex Rotation based Hopcroft-Karp (RVRHK) algorithm with the time complexity of O(N2.5), where N is the number of subcarriers. Because the theoretical analysis and the RVRHK algorithm are both based on the maximum matching method, the maximum frequency diversity in OFDMA systems is referred to as the max-matching diversity in this paper.

AB - This paper considers the problem of optimal subcarrier allocation in OFDMA systems to achieve the minimum outage probability while guaranteeing fairness. The optimal subcarrier allocation algorithm and the maximum frequency diversity gain are both analyzed through the maximum matching method based on the random bipartite graph theory. Accordingly, a surprising result is found, which shows that the maximum frequency diversity gain in subcarrier-sharing OFDMA systems is the same as that in point-to-point OFDM systems that serve only one user by using N subcarriers. It is then demonstrated that this maximum frequency diversity gain can be achieved by a proposed Random Vertex Rotation based Hopcroft-Karp (RVRHK) algorithm with the time complexity of O(N2.5), where N is the number of subcarriers. Because the theoretical analysis and the RVRHK algorithm are both based on the maximum matching method, the maximum frequency diversity in OFDMA systems is referred to as the max-matching diversity in this paper.

KW - Frequency diversity

KW - Maximum matching

KW - OFDMA

KW - Outage

KW - Random bipartite graph

UR - http://www.scopus.com/inward/record.url?scp=77950598718&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77950598718&partnerID=8YFLogxK

U2 - 10.1109/TCOMM.2010.04.080478

DO - 10.1109/TCOMM.2010.04.080478

M3 - Article

AN - SCOPUS:77950598718

VL - 58

SP - 1161

EP - 1171

JO - IEEE Transactions on Communications

JF - IEEE Transactions on Communications

SN - 0096-1965

IS - 4

M1 - 5439319

ER -