bryan@marlin.nosc.mil (Dale Bryan) (03/23/91)
I am currently working on a project that utilizes modems in an underwater acoustic data communications system. I am new to the project and don't know much about modems. Part of my tasking is to investigate what's new in the world of modems and to see if there are off-the-shelf units that are more capable than the ones that are being used now. The modems being used are 1981 vintage Rockwell R24 synchronous DPSK 2400 bps with fallback to 1200 bps. They are printed circuit board modules that require a host controller. They use V.26B and V.27bis formats. I am looking for replacement modems that may offer 2400 bps or higher at SNR-BER performance that is as good or better than 9dB for .00001 BER. I am particularly interested in anything using adaptive equalization and adaptive echo cancellation for long time delays as the acoustic channel can be very dispersive. Any help or insight into what's on the markets these days will be greatly appreciated. Dale Bryan (619)-553-1902 email: bryan@marlin.nosc.mil