Accession Number:

ADD019787

Title:

Method for Communication Using Adaptive Modem

Descriptive Note:

Patent Application, Filed 16 Nov 1999

Corporate Author:

DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s):

Report Date:

1999-11-16

Pagination or Media Count:

19.0

Abstract:

A method to improve communication system performance using an adaptive modem that estimates the communication channel scattering function to select one of several modulation schemes. The scattering function is estimated from the channels frequency doppler and time multipath spreading effects on a probe signal. The probe signal is transmitted from a first modem to a second modem. The second modem processes the channel measurements and transmits the channel spreading factors to the first modem. Based upon the channel scattering function estimate, channel characteristic data, propagation models, strategic information, and modem position estimates, the first modem selects one of several modulation schemes. Subsequent data transmissions from the first modem to the second modem contain a modulation mode identifier. The second modem uses the modulation mode identifier to select the correct demodulation scheme. Upon the occurrence of predetermined criteria, the channel scattering function estimate may be updated and a new modulation scheme.

Subject Categories:

  • Computer Hardware
  • Non-Radio Communications

Distribution Statement:

APPROVED FOR PUBLIC RELEASE