8 October 2015

CIS-128 broadband (6 KHz) waveform

Broadband waveform (6 KHz) of the CIS-128 OFDM modem. The values of the manipulation speed and carriers separation are the double of the ones seen in the 3 KHz waveform, i.e. 42 Baud  and 47 Hz, whilst the OFDM formation values remain unchanged (Pic. 1). The waveform allows the two 'data' and 'sync' modes, with the same 1-of-five character feature clearly visible in the data mode. Modulation is always QAM-16 (Pic. 2) and the ACF value is 10 symbols lenght (Pic. 3), like the narrow band waveform.

Pic. 1 - narrow band (3 KHz) and broadband (6 KHz) OFDM parameters
Pic. 2 - QAM-16 modulation in the channels
Pic. 3 -  10 symbols ACF

Below the screenshot of a CIS-128 BB reception (added as update on October, 10) on 14711.5 KHz on USB

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