Outage Perforformance of Power Controlled DS-CDMA Wireless Systems with Heterogeneous Traffic Sources

Abstract

This paper proposes a performance analysis of a Direct Sequence-Code Division Multiple Access (DS-CDMA) wireless system with heterogeneous traffic in terms of second order outage statistics. Imperfections in closed-loop power control are modelled in their first order distribution and autocorrelation function. System capacity and optimal power allocation has been previously derived [7] in the presence of requirements expressed only in terms of signal-to-(noise + interference) ratio and outage probability of every user in the system. Therefore, in this paper the effectiveness of power allocation is evaluated also in terms of average outage rate and average outage duration for the generic user link of each traffic class. This allows to gain insights on the effects of power allocation and feedback control on channel burstiness for each class of users, so that forward error correction and retransmission strategies can be properly tuned. With proper choice of system parameters, the proposed analysis can be applied to both the terrestrial and satellite segments of 3G systems, and integrated scenarios as well.