Analysis of uplink timing acquisition for SATCOM systems employing multiple chip-per-hop FH/DPSK

The authors investigate the performance of bit timing acquisition for antijam satellite communication systems which may use frequency-hopped differential phase shift keying (FH/DPSK) signaling with multiple data bits per hop. A bit timing acquisition system for these systems is described, and an analytical model is based on the circular state diagram approach of Polydoros and Weber (IEEE Trans. Commun., Vol. COM-32, p.1260-8, Dec. 1984; Vol. COM-32, p.542-60, May 1984), extended to previously unpublished results for cell-variable branch gain function coefficients. Performance results are presented for uplink acquisition with the example phase sequence and various system parameters, demonstrating the flexibility of the modified circular state model