公开(公告)号：CA2216128A1

公开(公告)日：1998-04-04

申请号：CA2216128

申请日：1997-09-23

Applicant: MOTOROLA INC

Inventor： SCHIRTZINGER TRACIE A ,  LAROSA CHRISTOPHER P

IPC: H03H21/00 ,  H03H17/02 ,  H03H17/06

Abstract: A digital filter (200) suitable for use in a CDMA or other burst-mode communication device (100) employs precombining of filter coefficients to reduce filter complexity and power dissipation. The digital filter (200) includes a coefficient storage circuit (216) for storing the precombined coefficients, a selection circuit (212) for selecting appropriate precombined coefficients in response to the input signal and a combining circuit (214) for combining the appropriate precombined coefficients to produce a filtered signal.

公开(公告)号：SG46286A1

公开(公告)日：1998-02-20

申请号：SG1996002146

申请日：1994-03-30

Applicant: MOTOROLA INC

Inventor： LAROSA CHRISTOPHER P ,  CARNEY MICHAEL J

IPC: G01R29/02 ,  H03L7/085 ,  H04B14/02 ,  H04L27/233 ,  H04L27/22

Abstract: A radio receiver directly digitizes the phase of an intermediate frequency (IF) signal with a desired resolution. The frequency of the reference oscillator in the direct phase digitizer is reduced when compared to the frequency previously required for the same resolution. The reduction in the reference oscillator frequency is accomplished by differentiating between IF zero-crossings that occur during the first half of a reference oscillator cycle and zero-crossings which occur during the second half of the reference oscillator cycle. The apparatus utilizes 2 zero-crossing detectors, the first zero-crossing detector is driven by a positive edge of the reference oscillator signal and the second zero-crossing detector is driven by a negative edge of the reference oscillator signal. Depending upon the alignment of the negative edge zero-crossing indicator and the positive edge zero-crossing indicator, the N-bit phase signal is modified or shifted by one-half a phase sector.

公开(公告)号：GB2314713A

公开(公告)日：1998-01-07

申请号：GB9710592

申请日：1997-05-23

Applicant: MOTOROLA INC

Inventor： LAROSA CHRISTOPHER P ,  CARNEY MICHAEL J

IPC: H03D3/00 ,  H04L27/14

Abstract: In the digital FM demodulator (330), a hard limiter (333) receives a modulated analog IF signal and limits the voltage of the IF signal to two levels. Next, a direct phase digitizer (336) uses zero-crossings of the limited IF signal to generate N-bit digital words. A phase differential circuit (340) computes the phase shift of the signal from the direct phase digitizer over a predetermined time interval. The dynamic range of the phase differential signal can be increased by replacing the phase differential circuit (340) with a high-resolution phase differential circuit. After digital demodulation and filtering and gain control by audio processor (360), the recovered signal is forwarded to a speaker (390) to produce an audio output. Thus, the digital FM demodulator both avoids problems common to analog discriminator circuitry and offers a reduced complexity, size, and power consumption alternative to conventional digital FM demodulators.

公开(公告)号：GB2277426B

公开(公告)日：1997-07-02

申请号：GB9406355

申请日：1994-03-30

Applicant: MOTOROLA INC

Inventor： LAROSA CHRISTOPHER P ,  CARNEY MICHAEL J

IPC: G01R29/02 ,  H03L7/085 ,  H04B14/02 ,  H04L27/233

Abstract: A radio receiver directly digitizes the phase of an intermediate frequency (IF) signal with a desired resolution. The frequency of the reference oscillator in the direct phase digitizer is reduced when compared to the frequency previously required for the same resolution. The reduction in the reference oscillator frequency is accomplished by differentiating between IF zero-crossings that occur during the first half of a reference oscillator cycle and zero-crossings which occur during the second half of the reference oscillator cycle. The apparatus utilizes 2 zero-crossing detectors, the first zero-crossing detector is driven by a positive edge of the reference oscillator signal and the second zero-crossing detector is driven by a negative edge of the reference oscillator signal. Depending upon the alignment of the negative edge zero-crossing indicator and the positive edge zero-crossing indicator, the N-bit phase signal is modified or shifted by one-half a phase sector.

公开(公告)号：GB2265526B

公开(公告)日：1995-09-13

申请号：GB9310244

申请日：1992-08-26

Applicant: MOTOROLA INC

Inventor： LAROSA CHRISTOPHER P ,  CARNEY MICHAEL J

IPC: H04B7/08 ,  H04B7/26

Abstract: A phase combining method and apparatus for use in a diversity reception radiotelephone is described. The phase combining method and apparatus is a hybrid diversity technique which combines elements of maximal ratio combining (MRC) and level comparison selection diversity, which results in a simple and effective implementation of a diversity receiver with superior performance. The diversity receiver demodulates the received signals, extracts the phase, forming two phase signals. Then, the two phase signals are combined to form a third phase signal. One of the three phase signals is selected to be used for interpretation of a symbol in the Quadrature Phase Shift Keying (QPSK) constellation. The selection process is based on the received signal strength of the received signals.

公开(公告)号：GB2269078B

公开(公告)日：1995-04-12

申请号：GB9314677

申请日：1993-07-15

Applicant: MOTOROLA INC

Inventor： LAROSA CHRISTOPHER P ,  CARNEY MICHAEL J

IPC: A61F13/15 ,  H04L27/233 ,  H03D7/00 ,  H03D13/00 ,  H04L27/22

Abstract: The present patent application discusses a frequency translation apparatus for altering the effective frequency of the phase information of an input signal (115). The input signal (115) has a first phase ((theta)(t)) and a first frequency (fi). The phase of the input signal is extracted and digitized at a second frequency (fo), forming a second N-bit digital phase signal ((theta)'(t))(311). The frequency translation apparatus generates a third digital phase signal (319) which approximates the difference between (theta)(t) and (theta)'(t). Then, the frequency translation apparatus combines the second digital phase signal and the third digital phase signal, forming a fourth digital phase signal (307) substantially approximating the first phase signal.

公开(公告)号：BR9205536A

公开(公告)日：1994-04-19

申请号：BR9205536

申请日：1992-10-13

Applicant: MOTOROLA INC

Inventor： LAROSA CHRISTOPHER P ,  CARNEY MICHAEL J

IPC: H03D3/00 ,  H04L7/033 ,  H04L27/233 ,  H03D3/18

Abstract: This patent application discusses a direct phase digitizing apparatus (303) for use in a radiotelephone (101). The direct phase digitizing apparatus (303) accepts a first analog signal (309) having a phase, a voltage range and a first frequency. First, the direct phase digitizer generates an estimated phase map (611) having a second frequency and N-bits of resolution. Second, the direct phase digitizer detects a predetermined-voltage crossing (409) of the first analog signal (309). Third, using the predetermined-voltage crossings, the direct phase digitizer samples the estimated phase map. Fourth, a digital phase signal (623) is generated using the samples of the estimated phase map.

公开(公告)号：CZ256493A3

公开(公告)日：1994-03-16

申请号：CZ256493

申请日：1993-01-21

Applicant: MOTOROLA INC

Inventor： LAROSA CHRISTOPHER P ,  CARNEY MICHAEL J

IPC: H04B7/26 ,  H04J3/06 ,  H04L7/00 ,  H04L7/033 ,  H04L27/22

公开(公告)号：GB2269078A

公开(公告)日：1994-01-26

申请号：GB9314677

申请日：1993-07-15

Applicant: MOTOROLA INC

Inventor： LAROSA CHRISTOPHER P ,  CARNEY MICHAEL J

IPC: A61F13/15 ,  H04L27/233 ,  H03D7/00 ,  H03D13/00 ,  H04L27/22

Abstract: The present disclosure includes a discussion of a frequency translation apparatus for altering the effective frequency of the phase information of an input signal (115). The input signal (115) has a first phase ( theta (t)) and a first frequency (fi). The phase of the input signal is extracted and digitized at a second frequency (fo), forming a second N-bit digital phase signal ( theta min (t)) (311). The frequency translation apparatus generates a third digital phase signal (319) which approximates the difference between theta min (t) and theta min (t). Then, the frequency translation apparatus (313) combines the second digital phase signal and the third digital phase signal, forming a fourth digital phase signal (307) substantially approximating the first phase signal.

公开(公告)号：CA2101527A1

公开(公告)日：1993-06-14

申请号：CA2101527

申请日：1992-09-21

Applicant: MOTOROLA INC

Inventor： LAROSA CHRISTOPHER P ,  CARNEY MICHAEL J

IPC: H04L27/233 ,  A61F13/15 ,  H03D7/00 ,  H03D13/00

Abstract: The present patent application discusses a frequency translation apparatus for altering the effective frequency of the phase information of an input signal (115). The input signal (115) has a first phase ((theta)(t)) and a first frequency (fi). The phase of the input signal is extracted and digitized at a second frequency (fo), forming a second N-bit digital phase signal ((theta)'(t))(311). The frequency translation apparatus generates a third digital phase signal (319) which approximates the difference between (theta)(t) and (theta)'(t). Then, the frequency translation apparatus combines the second digital phase signal and the third digital phase signal, forming a fourth digital phase signal (307) substantially approximating the first phase signal.