Interference diversity gain in frequency hopping GSM

Abstract

Wideband random frequency hopping is one of the key properties of GSM in an evolution towards PCS (personal communication services). Random frequency hopping introduces diversity on the transmission link, which improves the performance. In this paper, the impact of interference diversity in GSM is analyzed by means of bit level simulations of the GSM full rate speech channel. The analysis shows that the gain of interference diversity is highly system load dependent. The interference diversity gain is most striking in a system with low channel utilization. These results, together with system level simulations of frequency hopping GSM, show that random frequency hopping has implications for frequency planning. They indicate that GSM systems with simple frequency planning can be designed without sacrificing the overall system quality.