Evaluation of Welch-Costas Frequency Hopping Pattern for OFDM Cellular System

The performance of frequency hopped OFDM cellular system depends on the designing of frequency hopping sequences. This paper explores fast frequency hopped OFDM in the link level of a cellular communication system. Each user is assigned several sub-carriers by the base station in each cell in every time slot according to the predetermined hopping sequences. The frequency hopped OFDM technique based on orthogonal hopping sequences can improve communication performance in a cellular system since it could minimize intra-cell interference and average inter-cell interference. In this paper, Welch-Costas array pattern is derived under independent and cluster hopping schemes, which enable us to evaluate the system performance with the Turbo code modulation scheme. Examples of the frequency sequences and how they are assigned to users are also given. We also simulate and analyze the impacts of the channel environment and parameters, frequency diversity, and inter-cell interference diversity on the performance of the coded frequency hopped OFDM cellular system.