Performance of WCDMA1900 in the presence of uncoordinated narrow-band GSM interference

This paper studies the performance of WCDMA in the FCC PCS (1900 MHz) band in the presence of an uncoordinated adjacent narrow-band GSM interferer. The effect of the interference from GSM to WCDMA is evaluated assuming a 2×5-MHz spectrum allocation for WCDMA. These studies are based on computer simulations, utilising cell site configuration based on real-world market designs. The main outputs are coverage probability for voice & data services, capacity, other-to-own cell interference, and soft handover overhead. The results show that for 64 kbps data service the outdoor uplink coverage is greater than 99% in the study area. The voice capacity is 91 users per sector in the study area with 7.95 kbps adaptive multi-rate (AMR) voice codec rate. The total data throughput is 710 kbps per sector. These capacity values are close to the typical WCDMA dimensioning results with hexagonal grid, thus, showing that real-world site designs are suitable for WCDMA deployment. The effect of uncoordinated inter-system interference from the closest narrowband GSM carrier to the WCDMA downlink capacity is shown to have a negligible impact while maintaining the same coverage.