Frequency Hopping in LTE Uplink

Abstract: In the 3GPP LTE, different radio resource management (RRM) techniques have been proposed in order to improve the uplink performance. Frequency hopping is one of the techniques that can be used to improve the uplink performance by providing frequency diversity and interference averaging. The hopping can be between subframes (inter-subframe) or within a subframe (intra-subframe). 3GPP specifies two types of frequency hopping for the LTE uplink, hopping based on explicit hopping information in the scheduling grant and sub-band based hopping according to cell-specific hopping and mirroring patterns. In this master’s thesis, theoretical discussion on the frequency hopping schemes is carried out followed by dynamic simulations in order to evaluate the performance gain of frequency hopping. Based on the theoretical analysis, the second type of hopping is selected for detailed study. As a baseline for comparison, dynamic frequency domain scheduling with random frequency resource allocation has been used. Single cell and multi-cell scenarios have been simulated with VoIP traffic model using user satisfaction as a performance metric. The simulation results show that frequency hopping improves the uplink performance by providing frequency diversity in the single cell scenario and both frequency diversity and interference averaging in the multi-cell scenario. The gains in using the hopping schemes were reflected as VoIP capacity (the number of satisfied users) improvement. In this study, the performance of the selected hopping schemes under different hopping parameters is also evaluated.