Network planning models and algorithms for LTE-advanced cellular networks

One of the most important performance-limiting factors in wireless systems, specifically cellular systems, which limits the achievable data rates, is interference whether intra- or inter-cell. While intra-cell interference can be easily mitigated through the use of orthogonal resources such as frequencies in OFDM or codes in CDMA, decreasing the inter-cell interference is still a challenge. In Long Term Evolution (LTE) standard, all the Base Stations (BS), namely eNodeB, share the same spectrum. As a result the Inter Cell Interference (ICI) is sever, especially on the cell-edge UEs. Finding the efficient techniques to ameliorate the ICI in LTE networks is still open to question. The LTE networks Enhanced Inter Cell Interference Coordination (eICIC) schemes have been proposed to deal with interference in Heterogeneous Network (HetNet). These approaches can be divided into time domain techniques, such as Almost Blank Sub-Frames (ABSF), and frequency domain techniques. Their implementation relies on the use of some basic characteristics of the radio access technology used in the network. Deployment of ABSF as an Inter-Cell Interference Coordination (ICIC) technique to cope with inter-cell interference in LTE network and its effect on Network Planning Problem is under study in this thesis. Conventionally, ABSF is an ICIC technique that is used in HetNet. In this thesis, the application of ABSF technique is extended to the LTE, in general, and it is shown how the deployment of this technique is going to effect the Network Planning Problem in LTE-Advanced cellular network and wether ABSF can improve the performance of the network by improving the cell-edge performance, here enhancing the average of the rates of the users with lowest rate at their cells. In order to investigate whether applying ABSF would improve the rate of the cell-edge UEs, and weather the position of installed BSs would be changed, a Mixed Integer Linear Programming (MIPL) model is developed. Since finding the exact solution by the proposed MILP is time consuming, also a heuristic algorithm is developed.