Hybrid sequential acquisition schemes for noncoherent chip-asynchronous DS/SS systems

Abstract

This paper investigates the design and performance of hybrid sequential and nonsequential acquisition schemes for direct-sequence spread-spectrum (DS/SS) systems in the presence of multiple-access interference. Carrier phase and chip boundary information are not available at the time of acquisition. Simulation results show that the sequential scheme significantly outperforms the nonsequential scheme. For a DS/SS system using the sequential acquisition scheme, the acquisition-based capacity is evaluated and compared with the post acquisition-based capacity. Results show that for certain values of processing gain the system capacity is limited by the acquisition-based capacity.