| US 7,515,651 B1 | ||
| Parallel processing for programmable wideband digital modulation | ||
| Osama Sami Haddadin, Salt Lake City, Utah (US); L. Andrew Gibson, Jr., Riverton, Utah (US); and David Scott Nelson, Salt Lake City, Utah (US) | ||
| Assigned to L3 Communications Corporation, New York, N.Y. (US) | ||
| Filed on Aug. 07, 2003, as Appl. No. 10/637,946. | ||
| Int. Cl. H04L 27/20 (2006.01) | ||
| U.S. Cl. 375—308 [375/298; 332/103] | 5 Claims |

| 1. A circuit for up-sampling a digital data stream comprising:
a system clock defining a clock period;
a polyphase Nyquist filter, having as parallel inputs during one clock period, M in-phase symbols and M quadrature symbols
derived from a data stream, and outputting in parallel during one system clock period, k samples from each symbol, wherein
k is an integer greater than one and M is an integer greater than or equal to one;
an oscillator defining Mk first carrier wave outputs and Mk second carrier wave outputs, wherein each first carrier wave output
is in quadrature relation to a corresponding second carrier wave output;
a plurality of Mk in-phase multipliers, each in-phase multiplier having an input coupled to a first carrier wave output of
the oscillator and an input coupled to an output of the filter corresponding to an in-phase symbol;
a plurality of Mk quadrature multipliers, each quadrature multiplier having an input coupled to a second carrier wave output
of the oscillator and an input coupled to an output of the filter corresponding to a quadrature symbol;
a plurality of adders, each adder coupled to an output of an in-phase multiplier and an input coupled to an output of a quadrature
multiplier; and
a plurality of filter adders each having an input coupled to an output of at least two polyphase filter components that are
defined by the Nyquist filter.
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