Channel-gain matched macrodiversity in the forward link of cdma systems
Dongdong Li, J.A. Khoja, V.K. Prabhu · 2004
The orthogonality factor was used to simplify the expression of the E/sub b//N/sub 0/ of a mobile station communicating with a single base station in the forward link of CDMA systems. This paper extends the orthogonality factor to express the E/sub b//N/sub 0/ of a mobile station communicating with multiple base stations by using the channel-gain matched combination approach. A simplified expression of the E/sub b//N/sub 0/ is derived by averaging over fast fading and using average orthogonality factor. This new expression of E/sub b//N/sub 0/ simplifies the capacity and outage calculations of the CDMA systems in the forward link. The relationship between the average E/sub b//N/sub 0/ in practical CDMA systems and that obtained using the simplified model is discussed. The analysis shows that averaging over fast fading leads to a conservative evaluation of the CDMA system performance.