LIMITED K K K
US005949827A
Ulllted States Patent [19]
[11] Patent Number:
DeLuca et al.
[45]
[54]
5,949,827
Date of Patent:
Se . 7 a 1999
CONTINUOUS INTEGRATION DIGITAL
5,555,452
DEMODULATOR FOR USE IN A
5,563,537
9/1996 Callaway etal. .................. .. 455/226.6
COMMUNICATION DEVICE
5,627,860
5/1997 McKinney et al. .
5,802,462
9/1998
10/1996
Seta
....................
. . . ..
327/113
. 375/317
Lautzenhiser ......................... .. 455/208
[75] Inventors: Michael J. DeLuca, Austin, TeX.; Emilio J. Quiroga, Lake Worth, Fla.
[73] Assignee: Motorola, Inc., Schaumburg, Ill.
Primary Examiner—Chi H. Pham Assistant Examiner—Emmanuel Bayard Attorney) Agent) or Firm—]ames A. Lamb
[21] Appl. No.: 08/934,404
[57]
[22]
Filed.
A digital demodulator (100) for use in a communication
[51]
’ Int. Cl.6 ................................................... .. H04L 27/14
Sep_ 19 1997
ABSTRACT
device comprising a mixer (110) Which samples a limited IF signal derived from a received radio frequency (RF) signal
[52]
US. Cl. ,,,,,,,,,,,,,,,, ,,
_ 375/324; 375/340; 455/255
at a rate less than a Nyquist rate of the limited IF signal and
[58]
Field of Search ................................ .. 375/316, 322,
generates a resulting IF signal- ACOIltiIlllOllS integrator (130)
375/324, 340; 329/315, 321, 323; 455/205, 208, 210, 255, 673, 63, 501; 365/7241
is connected to the mixer (110) and integrates the resulting IF signal over a predetermined number of samples thereof to generate a numerical value representative of a modulation
[56]
References Cited
frequency of a limited IF signal. An adaptive peak-valley bit slicer (150) is connected to the continuous integrator (130)
US‘ PATENT DOCUMENTS
and compares each numerical value With a peak threshold,
4,631,737
12/1986 Davis et al. ............................ .. 375/88
4,816,820 3/1989 Davis ,,,,,,,,,,,,, ,, 5,058,204 10/1991 Tahernia et al. . 5,109,544 4/ 1992 Mittel et al- -572227255
340/825 455/183 455/182-2
6/1993 K110 ct a1~
5274579 12/1993 Nelson et a1‘ 5,303,416
4/1994 Morera ........... ..
5,311,554
5/1994 Morera et a1.
~~~~~ ~~ 455/226
a level of a current numerical value based on the LSB and
" 364/72409
MSB values determined for a prior sample of the numerical
455/296
Value
375/75
5,376,894 12/1994 Petranovich 5,425,056
4 Valley threshold and a mid threshold and generates most
signi?cant-bit (MSB) and least-signi?cant-bit (LSB) values for each sample. The adaptive peak-valley bit slicer (150) adjusts the peak and valley thresholds for use in determining
'
329/306
6/1995 Maroun et a1. ....................... .. 375/316
29 Claims, 5 Drawing Sheets
/ LIMITED
K
'F S'GNAL FROM
110
K
130
150
DOWN SAMPLING/
CONTINUOUS
PéAIE’QCXKEEY
ALIASING MIXER
INTEGRATOR
BIT SUCER
'
RECEIVER
I:C,
F0’ 180
FREQUENCY DIvIDER ./
f
K
170
OSCILLATOR
Fe
100
DIGITAL '
DATA
U.S. Patent
Sep.7, 1999
Sheet 1 of5
5,949,827
as
05K
NEE~
U.S. Patent
Sep.7, 1999
Sheet 2 of5
5,949,827
U.S. Patent
Sep.7, 1999
Sheet 4 0f 5
5,949,827
ADAPTIVE BIT SLFCING PEAK & VALLEY THRESHODS
LAST SAM
TH HI
NEXT SAMPLE TH MID
TH LO
1O 11 O1 O0
(
FIG. 5
FIG. 6
U.S. Patent
Sep.7, 1999
Sheet 5 of5
5,949,827
mokz mwzotg
-
"I. I "QSIK8m\QGK
0mm H H
E05 3m\
-
E O D P I _ < w F m J D O § M \k_wnozE:FNoOmIQZG
\ m2 " " 8w " _GO“
"“zo_m.wz
Ulllted States Patent [19]
[11] Patent Number:
DeLuca et al.
[45]
[54]
5,949,827
Date of Patent:
Se . 7 a 1999
CONTINUOUS INTEGRATION DIGITAL
5,555,452
DEMODULATOR FOR USE IN A
5,563,537
9/1996 Callaway etal. .................. .. 455/226.6
COMMUNICATION DEVICE
5,627,860
5/1997 McKinney et al. .
5,802,462
9/1998
10/1996
Seta
....................
. . . ..
327/113
. 375/317
Lautzenhiser ......................... .. 455/208
[75] Inventors: Michael J. DeLuca, Austin, TeX.; Emilio J. Quiroga, Lake Worth, Fla.
[73] Assignee: Motorola, Inc., Schaumburg, Ill.
Primary Examiner—Chi H. Pham Assistant Examiner—Emmanuel Bayard Attorney) Agent) or Firm—]ames A. Lamb
[21] Appl. No.: 08/934,404
[57]
[22]
Filed.
A digital demodulator (100) for use in a communication
[51]
’ Int. Cl.6 ................................................... .. H04L 27/14
Sep_ 19 1997
ABSTRACT
device comprising a mixer (110) Which samples a limited IF signal derived from a received radio frequency (RF) signal
[52]
US. Cl. ,,,,,,,,,,,,,,,, ,,
_ 375/324; 375/340; 455/255
at a rate less than a Nyquist rate of the limited IF signal and
[58]
Field of Search ................................ .. 375/316, 322,
generates a resulting IF signal- ACOIltiIlllOllS integrator (130)
375/324, 340; 329/315, 321, 323; 455/205, 208, 210, 255, 673, 63, 501; 365/7241
is connected to the mixer (110) and integrates the resulting IF signal over a predetermined number of samples thereof to generate a numerical value representative of a modulation
[56]
References Cited
frequency of a limited IF signal. An adaptive peak-valley bit slicer (150) is connected to the continuous integrator (130)
US‘ PATENT DOCUMENTS
and compares each numerical value With a peak threshold,
4,631,737
12/1986 Davis et al. ............................ .. 375/88
4,816,820 3/1989 Davis ,,,,,,,,,,,,, ,, 5,058,204 10/1991 Tahernia et al. . 5,109,544 4/ 1992 Mittel et al- -572227255
340/825 455/183 455/182-2
6/1993 K110 ct a1~
5274579 12/1993 Nelson et a1‘ 5,303,416
4/1994 Morera ........... ..
5,311,554
5/1994 Morera et a1.
~~~~~ ~~ 455/226
a level of a current numerical value based on the LSB and
" 364/72409
MSB values determined for a prior sample of the numerical
455/296
Value
375/75
5,376,894 12/1994 Petranovich 5,425,056
4 Valley threshold and a mid threshold and generates most
signi?cant-bit (MSB) and least-signi?cant-bit (LSB) values for each sample. The adaptive peak-valley bit slicer (150) adjusts the peak and valley thresholds for use in determining
'
329/306
6/1995 Maroun et a1. ....................... .. 375/316
29 Claims, 5 Drawing Sheets
/ LIMITED
K
'F S'GNAL FROM
110
K
130
150
DOWN SAMPLING/
CONTINUOUS
PéAIE’QCXKEEY
ALIASING MIXER
INTEGRATOR
BIT SUCER
'
RECEIVER
I:C,
F0’ 180
FREQUENCY DIvIDER ./
f
K
170
OSCILLATOR
Fe
100
DIGITAL '
DATA
U.S. Patent
Sep.7, 1999
Sheet 1 of5
5,949,827
as
05K
NEE~
U.S. Patent
Sep.7, 1999
Sheet 2 of5
5,949,827
U.S. Patent
Sep.7, 1999
Sheet 4 0f 5
5,949,827
ADAPTIVE BIT SLFCING PEAK & VALLEY THRESHODS
LAST SAM
TH HI
NEXT SAMPLE TH MID
TH LO
1O 11 O1 O0
(
FIG. 5
FIG. 6
U.S. Patent
Sep.7, 1999
Sheet 5 of5
5,949,827
mokz mwzotg
-
"I. I "QSIK8m\QGK
0mm H H
E05 3m\
-
E O D P I _ < w F m J D O § M \k_wnozE:FNoOmIQZG
\ m2 " " 8w " _GO“
"“zo_m.wz
