Louay Jalloul

High speed downlink packet access performance

The overall throughout and delay performance of the 1XTREME proposal in 3GPP2 and the HSDPA proposal in 3GPP are provided. The performance sensitivity to call model, peak data rate, hybrid ARQ, C/I feedback delay, and multipath interference is examined using a quasistatic system simulator. In all cases, performance is bounded using two simple scheduling approaches, maximum C/I and round robin.

Performance analysis of CDMA transmit diversity methods

The link performance of transmit diversity (TD) schemes for third generation CDMA systems is analyzed. Orthogonal transmit diversity (OTD) and space-time transmit diversity (STTD) are compared. It is shown that the link performances of OTD and STTD are nearly the same. However, STTD requires additional receiver processing, and STTD is not directly extendable to more than 2 antennas, because rate one space-time block codes do not exist for greater than 2 antennas. Also, an interleaving approach is shown that works for various TD schemes as well as non-TD.

Air-interface for 1XTREME/1xEV-DV

A high data rate proposal for a 1.25 MHz DS-CDMA system, called 1XTREME (1xEV-DV), is capable of supporting peak rates of up to 4.8 Mbps and average data rates of approximately 1 Mbps. It is a true evolution of the cdma-2000 CDMA system, being fully backward compatible and therefore able to support both voice and data users on the same carrier. A new forward shared channel (F-SHCH) with an associated forward control channel carries the high-speed packet data. The associated forward control channel structure is shown to offer a 30% increase in the active users on the system over a typical structure. Furthermore, additional channels are added in the reverse link to support the various throughput-enhancing features of 1XTREME. In this paper, the details of the air-interface are presented along with the description of each channel. Also, the simulated performance of the F-SCH and the forward control channels are presented.

CDMA forward link capacity in a flat fading channel

The performance of the forward link for an IS-95 based CDMA system in case of slowly moving mobiles in a flat Rayleigh fading channel is evaluated. It is shown that soft handoff improves the system capacity at the expense of an increase in the hardware requirements at the cell site. The analysis shows the interaction between the design parameters and their effect on system performance. Outage, blocking and coverage probabilities are defined and used to characterize system performance.