The command post on the move

The author describes the operation at 24 Mb/s of a broadband code-division multiple-access (B-CDMA) system employing nonlinear codes for security. Users in this system can transmit toll quality voice using 32-kb/s adaptive delta modulation or data at rates up to T1. The antennas employed are omnidirectional, and the acquisition and tracking systems can follow Doppler shifts to 1 part in 10/sup 5/. Handoff from one base station to another occurs smoothly without loss of data. Experimental results are presented to verify theory. It is shown that such a system by virtue of its 48-MHz bandwidth and the low data rate has a processing gain of approximately 40 dB. Thus, the power spectral density of the transmitted signal is reduced by 40 dB compared to a narrowband transmission. As a result, B-CDMA is inherently LPI (low probability of interception).<<ETX>>

[1]  D.L. Schilling,et al.  Broadband CDMA for personal communications systems , 1991, IEEE Communications Magazine.

[2]  D.L. Schilling,et al.  Spread spectrum for commercial communications , 1991, IEEE Communications Magazine.

[3]  Laurence B. Milstein,et al.  On the Feasibility of a CDMA Overlay for Personal Communications Networks , 1992, IEEE J. Sel. Areas Commun..

[4]  Donald L. Schilling,et al.  Propagation loss and adaptive power control for a broadband-CDMA communication system in a mobile tactical environment , 1992, MILCOM 92 Conference Record.

[5]  Saeed S. Ghassemzadeh,et al.  Propagation modeling and measurements in an urban and suburban environment using broadband direct sequence spread spectrum , 1992, [1992 Proceedings] Vehicular Technology Society 42nd VTS Conference - Frontiers of Technology.

[6]  L. B. Milstein,et al.  Cell design for a broadband CDMA personal communications network , 1992, [Conference Record] SUPERCOMM/ICC '92 Discovering a New World of Communications.