LTE System Performance in Relation to Wideband Channel Properties

Abstract

In the current radio planning of wireless cellular networks, analysis of system performance is based on Signal to Noise Ratio (SNR). However, for wideband system such as LTE, the performance depends not only on the SNR but also on the amount of frequency and spatial diversity that the system can exploit. These diversities rely on the delay and angular profile of the radio channel which are often quantified in terms of delay spread (DS) and angular spread (AS). From an operator’s point of view, in order to get reliable prediction of network capacity and coverage, delay spread and angular spread should therefore be taken into account in the radio planning. In this thesis, the effect of delay spread and angular spread on LTE system performance is investigated by performing LTE system level simulations. LTE system level simulation models AMC (Adaptive Modulation and Coding) hence it aligns with how the system works in reality. However, to implement AMC, system level simulation needs an accurate prediction of link level performance in terms of BLER. For this reason, AWGN link level simulation is required. The simulation results show that different delay spread values do not significantly affect the performance of LTE. This indicates that delay spread is not an important parameter to be taken into account in LTE radio planning. On the other hand, first result shows that per path angular spread strongly affects the performance of LTE. This suggests that it should be included in the radio planning of LTE.