Patents by Inventor Christopher J. Chrin

Christopher J. Chrin has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4577287
    Abstract: A method of generating the digital representation of a sine wave. A digital signal processor is used to generate the sample digital values, spaced at period T, of a sine wave of frequency F, using the value of the previous sample, e, the corresponding value of cosine, f, and two constants, c=sin2.pi.FT and d=cos2.pi.FT. The next value of sine, S=ed+cf; the value of the corresponding cosine, C=df-ce. The magnitude of c and d are rounded up so that c.sup.2 +d.sup.2 .gtoreq.1. Any calculated values of S or C which exceed unity in magnitude are limited to a magnitude of unity. This limiting operation accomplishes the normalization operation necessary to avoid exponential build-up due to accumulated round-off errors, and does so more efficiently than was previously possible. Sine waves with a 50 dB signal to noise ratio have been generated using this method.
    Type: Grant
    Filed: March 2, 1983
    Date of Patent: March 18, 1986
    Assignee: AT&T Bell Laboratories
    Inventor: Christopher J. Chrin