Performance improvement in GSM networks due to slow frequency hopping

Abstract

This paper investigates the performance of GSM systems employing slow frequency hopping when a limited number of hopping channels are used. Frequency hopping increases spectral efficiency by enabling frequencies to be reused more intensely. Previous analysis of frequency hopping systems have considered systems that have a large number of hopping channels available. However, due to spectrum and frequency planning constraints, there are often only a limited number of channels available for hopping in most cellular systems and consequently maximum improvement cannot be achieved. The performance of such a system is evaluated and a comparison made between frequency hopping and intra-timeslot handover. Intra-timeslot handover is found to have better interference immunity performance than two channel frequency hopping when the mean C/I is less than approximately 16 dB in both the urban and suburban environments. The results show that the performance of frequency hopping surpasses that of intra-timeslot handover as more hopping channels are deployed.