Link error prediction for wireless system simulations

A link error prediction (LEP) methodology allows the abstraction of link performance into system level studies, so that system performance may be characterized efficiently. The quasi-static method (QSM) method (http://www.3gpp2.org) (R. Ratasuk et al., 2002) which assumes perfect channel quality estimates for demodulation, has been widely used for downlink system performance evaluation. However, unlike in the downlink, the per-user uplink pilot, which is power-controlled, is much weaker, so that channel estimation errors, and its effect on link performance (especially at high data rates), is considerably higher. In this paper we propose a simple and efficient LEP method, which we call the equivalent SNR method (ESM), for analytically capturing the effect of channel estimation errors on link performance. ESM is shown to he extremely accurate over a wide range of pilot SNRs. We note that ESM was adopted for LEP for cdma2000 (EVDV) and UMTS system simulations.