Claims
- 1. A subscriber unit comprising:
a processor, for providing an output phase signal corresponding to a selected output digital frequency; a tuning register for buffering said phase signal; a lookup table having two sets of predefined stored values pertaining to the amplitude of a signal for single quadrant, wherein said predefined stored values comprise coarse angle approximations and fine angle approximations; a sine and cosine generator for receiving said phase signal and generating sine and cosine waveforms utilizing amplitude values obtained from said lookup table, wherein said phase signal includes phase data and specifies the quadrant and the algebraic sign of the phase data; said sine and cosine generator accessing said lookup table differently depending upon the quadrant and sign of the phase data such that the lookup table provides an amplitude value from said sets of predefined stored values based upon the phase data; and a modulator for combining the sine and cosine waveforms to produce said selected output digital frequency and for modulating said digital frequency.
- 2. The subscriber unit of claim 1 wherein the lookup table includes a first table having values pertaining to large angle approximations for coarse resolution frequency adjustment of the digital frequency and a second table for stored values pertaining to small angle approximation for fine resolution frequency adjustment.
- 3. The subscriber unit of claim 2 wherein the size of said first and second tables is reduced using trigonometric decompression.
Parent Case Info
[0001] This application is a continuation of application Ser. No. 09/593,307, filed Jun. 13, 2000; which is a continuation of application Ser. No. 09/228,140, filed Jan. 11, 1999, now U.S. Pat. No. 6,078,629, issued on Jun. 20, 2000; which is a continuation of application Ser. No. 08/881,339, Jun. 24, 1997, now U.S. Pat. No. 5,859,883, issued on Jan. 12, 1999; which is a continuation of application Ser. No. 08/587,008, filed Jan. 11, 1996, now U.S. Pat. No. 5,694,430, issued Dec. 2, 1997; which is a continuation of application Ser. No. 08/445,082, filed May 22, 1995, now U.S. Pat. No. 5,644,602, issued Jul. 1, 1997; which is a divisional of application Ser. No. 08/222,670, filed Apr. 4, 1994; which is a continuation of 07/940,662, filed Sep. 4, 1992, now U.S. Pat. No. 5,325,396, issued Jun. 28, 1994; which is a continuation of application Ser. No. 07/658,065, filed Feb. 20, 1991, Now U.S. Pat. No. 5,146,473, issued Sep. 8, 1992; which is a continuation of application Ser. No. 07/394,497, filed Aug. 14, 1989, now U.S. Pat. No. 5,008,900, issued Apr. 16, 1991.
Divisions (1)
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Number |
Date |
Country |
Parent |
08222670 |
Apr 1994 |
US |
Child |
08445082 |
May 1995 |
US |
Continuations (8)
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Number |
Date |
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Parent |
09593307 |
Jun 2000 |
US |
Child |
10223750 |
Aug 2002 |
US |
Parent |
09228140 |
Jan 1999 |
US |
Child |
09593307 |
Jun 2000 |
US |
Parent |
08881339 |
Jun 1997 |
US |
Child |
09228140 |
Jan 1999 |
US |
Parent |
08587008 |
Jan 1996 |
US |
Child |
08881339 |
Jun 1997 |
US |
Parent |
08445082 |
May 1995 |
US |
Child |
08587008 |
Jan 1996 |
US |
Parent |
07940662 |
Sep 1992 |
US |
Child |
08222670 |
Apr 1994 |
US |
Parent |
07658065 |
Feb 1991 |
US |
Child |
07940662 |
Sep 1992 |
US |
Parent |
07394497 |
Aug 1989 |
US |
Child |
07658065 |
Feb 1991 |
US |