CLOVER2000

CLOVER is the name of a series or class of modem modulation techniques (“waveforms”) specifically designed for use over high frequency (HF) radio systems.

* CLOVER-II was the first CLOVER waveform sold commercially, developed by Ray Petit and HAL Communications in 1990-92.
* CLOVER-2000 is a higher-rate and wider bandwidth version of CLOVER developed in 1995.
* CLOVER-400 is a special 400Hz wide waveform that was developed for Globe Wireless.

Modulation schemes

In ARQ mode, all CCB’s (CLOVER Control Blocks) use BPSM modulation and data blocks may be sent using BSPM, QPSM, 8PSM, 8P2A, or 16P4A modulation. Data is sent in 255-byte blocks. The FEC broadcast mode of CLOVER-2000 is usually disabled although special formats are available for specific applications.

Radio Interface requirements for CLOVER-2000

The CLOVER waveform offers high performance, error correction, and spectral efficiency. CLOVER is specifically designed for use over HF radio communications links. It may be used with virtually any modern HF SSB radio. However, certain special set-up and adjustment techniques are required to get maximum performance when using CLOVER.

See also

* shortwave
* radioteletype
* PSK31
* PACTOR
* SITOR