There has been some additional development of parts reported in “Multi-Modulator for Bandwidth-Efficient Communication” (NPO-40807), NASA Tech Briefs, Vol. 32, No. 6 (June 2009), page 34. The focus was on:

  • The generation of M-order quadrature amplitude modulation (M-QAM) and octonary-phase-shift-keying, trellis-coded modulation (8PSK TCM),
  • The use of square-root raised-cosine pulse-shaping filters,
  • A parallel-processing architecture that enables low-speed [complementary metal oxide/semiconductor (CMOS)] circuitry to perform the coding, modulation, and pulse-shaping computations at a high rate; and
  • Implementation of the architecture in a CMOS field-programmable gate array.

This work was done by Andrew Gray and Dennis Lee of Caltech; Scott Hoy of Lockheed- Martin; Dave Fisher of SGT Inc.; Wai Fong and Parminder Ghuman of GSFC for NASA’s Jet Propulsion Laboratory. For more information, contact This email address is being protected from spambots. You need JavaScript enabled to view it.. NPO-40809

NASA Tech Briefs Magazine

This article first appeared in the September, 2009 issue of NASA Tech Briefs Magazine.

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