Interference impact of WCDMA mobile station on IS-95 Mobile Station performance

Improper spectrum allocation of PCS 1900 band (IS- 95) and IMT2000 band (WCDMA) in the same geographical area may cause severe interference between those two technologies. As a result inefficiency of spectrum usage is unavoidable, drop calls, and or outage probability of the interference victim (IS-95 Mobile Station) may reach an intolerable level. Therefore, a minimum guard band and or a Minimum Separation Distance are required to reduce the interference impact. Considering the SIR and receiver sensitivity as the reference level, a simulation is developed in this research to find the outage probability assuming that mobile stations are uniformly distributed in the cell with an downlink macro cell propagation model. The results showed, in an environment with a lognormal shadowing deviation standard of 10 dB and 10 MHz guard band, the victim need to be separated 20 m from the WCDMA mobile station in order to obtain outage probability less than 1% if no additional filter is installed.