Loading...

Analysis and Improvement of Resource Allocation in 5th Generation of Mobile Networks

Elhami, Golnoosh Sadat | 2015

627 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 47292 (05)
  4. University: Sharif University of Technology
  5. Department: Electrical Engineering
  6. Advisor(s): Pakravan, Mohammad Reza
  7. Abstract:
  8. Ever growing users’ demand for data traffic rate in mobile networks، the strict limitations on available spectrum، reducing operators’ expenditures for higher achievable revenue and also supporting significant number of simultaneous users in the network are among the most important drivers and motivations of operators to devise new structures in their current networks. One of the proposed structures aimed at offloading the traffic from cellular networks and responding to the requirements of 5th generation of mobile networks is direct device to device communications underlaying cellular networks. Interference management and proper frequency-time resource allocation should be taken under consideration in device to device communications. Regarding limitations on available frequency and time resources in the networks، it can be imagined that the resources should be shared among device to device communications and conventional cellular users in either orthogonal or non-orthogonal ways. From resource management point of view، resource allocation can be classified in three different categories، centralized، distributed and semi-distributed schemes. In this thesis، we investigate three various resource allocation approaches in device to device networks. In the first scenario، the resource allocation problem aimed at maximizing the number of communicating pairs as well as reducing the number of consumed time-frequency resources is formulated. By assuming centralized and orthogonal resource sharing، this problem is formulated by an optimization model. Based on graph theoretic concepts، near-optimal solution is proposed that offers much less time and computational complexity compared to the existing approaches. In the second scenario، non-orthogonal، QoS-guaranteed resource sharing is considered assuming centralized scheme. In this scenario، the near-optimal solutions are obtained by decomposing the optimization modeling of the problem and utilizing three-step proposed scheme. The objective of this problem is to maximize the users’ sum throughput subject to keeping the users’ sensed interference lower than a pre-defined threshold. In the third scenario، we seek to allocate resources in an orthogonal semi-distributed manner. Also، we propose some novel methods in order to alleviate the effect of interfering communications. In all the scenarios that have been investigated in this research، we consider practical assumptions which were neglected in literature. Simulation results approve the high efficiency of the proposed algorithms in different scenarios
  9. Keywords:
  10. Resources Allocation ; 3th Generation of Mobile ; Fifth Generation of Mobile Networks ; Device to Device Communications ; Peer Selection Problem ; Cellular Users

 Digital Object List

 Bookmark

No TOC