Training-feedback tradeoff in closed-loop synchronous DS-CDMA systems with adaptive user sequences

This paper considers a synchronous DS-CDMA system where channel state information at the base station is acquired via uplink training and channel feedback is used to provide the terminals with the optimal uplink signatures. We examine the tradeoffs involved in the proportioning of a resource block between training, data, and feedback symbols, with linear (matched filter and minimum mean-square error) receive processing at the BS with the user rate as the performance metric. Simulation results are presented to corroborate the analytical discussion.