Datum Systems now offers improved Low Excess Bandwidth (Alpha) Filtering, in its new M7 line of Modems that allow carrier spacing at frequency offsets below 10% of the symbol rate. Datum currently offers down to a 5% Alpha, which means that carriers can be spaced at 1.05 times the symbol rate instead of the historical factor of 1.35. This allows an immediate spectral efficiency increase of 28.5%, resulting in 22% bandwidth savings. Filter Roll-Off options in the new M7 modems Series include 5%, 8%, 10%, 15%, 20%, 25%, 30%, 35% and 40%. These selections are standard options on the M7 via the front panel or remote interfaces.
Datum continues to save you money with more bandwidth efficient features in its new low cost M7 Series Satellite Modems.
The pioneers of Advanced Flexible LDPC coding have now added Sharper TX/RX Filter Roll-Off’s to its bandwidth reducing line-up.
The spectrum analyzer plot (Fig. 1) shows 3 16QAM carriers spaced at 1.08 times the symbol rate of 1 MHz. The center carrier is disadvantaged by 10 dB, which is unlikely to occur on a satellite, but used to provide a worst case scenario. The demodulator for the center carrier reports an Eb/N0 of 30 dB, which is the measurement limit for the Datum M7 demod. This means that there is no measurable degradation in the Datum M7 modems for 16QAM at a carrier spacing of 1.08 x Symbol.
With higher transponder lease costs of up to $3500/MHz/Month, the new Sharp Carrier technique cuts the occupied bandwidth by 34% while maintaining power balance. This in turn cuts the lease cost by up to 34%, or $1500/month, generally resulting in a payback time of less than 3 months.
This important advancement provides greater satellite bandwidth utilization and efficiency. If you are leasing transponder space for multicarrier, and your spacing is more than 1.25 times the symbol rate, Datum advanced filtering techniques in the M7 can save you 30% or more of your transponder lease cost.
Learn more by downloading Datum´s Sharp Carrier White Paper:
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