Frequency coordination between adjacent carriers of two CDMA operators

Frequency coordination is the process that assigns frequency bands to neighboring or coexisting systems to minimize interference. This interference is caused by unwanted signals from adjacent frequency bands. Especially, interference is maximized by the spatial near-far problem which occurs in the case where two different cellular systems serve. This critical case happens when different cellular operators using the adjacent carriers do not collocate their base stations (BS). We investigate the frequency coordination when two CDMA operators using adjacent CDMA carriers don´t collocate their BS. In order to lessen the unwanted interference we put a guard band which separates adjacent carriers. This paper presents the simulation and laboratory test results used to analyze the guard bandwidth requirement. For the guard band simulation, we derive theoretical interference prediction models which calculate the quantity of unwanted interference. Additionally, this paper confirms the accuracy of the theoretical models with a series of laboratory test. The results assert the necessity for the guard band and discover the relation between the guard band and the service quality