公开(公告)号：GB2267632A

公开(公告)日：1993-12-08

申请号：GB9312029

申请日：1992-08-14

Applicant: MOTOROLA INC

Inventor： MUELLER BRUCE D ,  BORTH DAVID E ,  BAUM KEVIN L

IPC: H03M13/41 ,  H04L25/03 ,  H04L27/22 ,  H04L25/08 ,  H03D1/00 ,  H03D3/22 ,  H03H7/30 ,  H03H7/40

Abstract: A system and method for calculating survivor metrics in a Viterbi equalizer (424) of a receiver (56), such as a receiver operative to receive a PSK-modulated signal, for example, a pi /4, differential, phase-shift-keying, modulated signal. The state transition metric, defined as a function of two successive states, is converted into a function defined by pairwise differences between allowable symbols of the PSK-modulated signal. When operative to receive pi /4 DQPSK-modulated signal, the number of calculations required to calculate state transition metrics is reduced significantly.

公开(公告)号：FI934361A0

公开(公告)日：1993-10-04

申请号：FI934361

申请日：1993-10-04

Applicant: MOTOROLA INC

Inventor： BORTH DAVID E ,  HAUG JOHN R ,  RASKY PHILLIP D

IPC: H04B7/26 ,  H04W74/04

公开(公告)号：FR2679085A1

公开(公告)日：1993-01-15

申请号：FR9208044

申请日：1992-06-30

Applicant: MOTOROLA INC

Inventor： MUELLER BRUCE D ,  BAUM KEVIN L ,  BORTH DAVID E ,  RASKY PHILLIP D ,  WINTER ERIC H

IPC: H04B3/04 ,  H04B7/00 ,  H04B7/005 ,  H04B7/08 ,  H04L1/02 ,  H04L25/06 ,  H04L27/01 ,  H04L27/22 ,  H04B17/00

Abstract: A system and method for correcting for Rayleigh interference of a signal transmitted upon a multi-path channel. The system adaptively calculates values of channel gain and noise variance of the channel upon which the signal is transmitted, and generates signals indicative of such calculations which are supplied to a decoder. The system may be utilized to form a portion of a coherent, or noncoherent receiver which receives encoded and differentially-encoded signals.

公开(公告)号：SE9203808L

公开(公告)日：1993-01-03

申请号：SE9203808

申请日：1992-12-18

Applicant: MOTOROLA INC

Inventor： MUELLER BRUCE D ,  BAUM KEVIN L ,  BORTH DAVID E ,  RASKY PHILIP D ,  WINTER ERIC H

IPC: H04B3/04 ,  H04B7/00 ,  H04B7/005 ,  H04B7/08 ,  H04L1/02 ,  H04L25/06 ,  H04L27/01 ,  H04L27/22 ,  H04L1/20

Abstract: A system and method for correcting for Rayleigh interference of a signal transmitted upon a multi-path channel. The system adaptively calculates values of channel gain and noise variance of the channel upon which the signal is transmitted, and generates signals indicative of such calculations which are supplied to a decoder. The system may be utilized to form a portion of a coherent, or noncoherent receiver which receives encoded and differentially-encoded signals.

公开(公告)号：CA2075051A1

公开(公告)日：1992-08-29

申请号：CA2075051

申请日：1992-02-12

Applicant: MOTOROLA INC

Inventor： BORTH DAVID E ,  RASKY PHILLIP D ,  LING FUYUN ,  EYUBOGLU M VEDAT

IPC: H03H15/00 ,  H03H17/00 ,  H03H21/00 ,  H03M13/00 ,  H03M13/23 ,  H04B1/10 ,  H04B1/12 ,  H04B3/14 ,  H04B7/005

Abstract: A signal weighting system for associating a confidence level with portions of a communication signal transmitted upon a multipath channel and received by a receiver. A signal received by the receiver is equalized by an equalizer circuit, such as a maximum likelihood sequence estimator, and the equalized signal generated thereby is supplied to an adaptive filter which is synthesizes portions of the multipath channel. The signal received by the receiver is altered responsive to values of a filtered, equalized signal generated by the adaptive filter.

公开(公告)号：CA2062776A1

公开(公告)日：1991-10-28

申请号：CA2062776

申请日：1991-04-09

Applicant: MOTOROLA INC

Inventor： ARENS JOHN W ,  BORTH DAVID E ,  KEPLER JAMES F M

IPC: H04B1/16 ,  H03G3/20 ,  H04B1/30 ,  H04B7/005 ,  H04L27/14 ,  H04L27/22

Abstract: There is provided a mechanism for Automatic Gain Control in a receiver. It comprises: determining, within a certain dynamic range, the difference in power between the desired signal and a signal received, and providing open loop gain control for the signal in response to the differential so determined, scaled by the receiver's gain characteristics, such that the signal is positioned within dynamic range so as to reduce saturation and noise.

公开(公告)号：CA1291280C

公开(公告)日：1991-10-22

申请号：CA576640

申请日：1988-09-07

Applicant: MOTOROLA INC

Inventor： BORTH DAVID E ,  WANG CHI-FEI ,  RABE DUANE C ,  LABEDZ GERALD P

IPC: H04L27/22 ,  H04B7/185 ,  H04B7/26 ,  H04J3/00 ,  H04L7/04 ,  H04B7/212

Abstract: PHASE-COHERENT TDMA QUADRATURE RECEIVER FOR MULTIPATH FADING CHANNELS of the Invention A method and apparatus for phase-coherently demodulating a multipath-impaired time division multiple access QPSK data timeslot is disclosed. A quadrature separator generates multipath-impaired intermediate signals which, during a predetermined synchronizing sequence for the timeslot, are applied to a pair of synchronizing correlators to generate quadrature multipath profiles. These profiles then are used to modify subsequently received QPSK timeslot signals at the separator outputs to coherently construct multipath compensated I and Q channel data.

公开(公告)号：DD292789A5

公开(公告)日：1991-08-08

申请号：DD33574189

申请日：1989-12-15

Applicant: MOTOROLA INC

Inventor： BORTH DAVID E ,  KEPLER JAMES F M

IPC: H03L7/095 ,  H03J7/02 ,  H03L7/08 ,  H03L7/087 ,  H03J7/18

Abstract: There is provided a method of and apparatus for Automatice Frequency Control (AFC) of pure sine waves (PSW). It is characterized by discriminating to detect frequency differences between a received pure sine wave and a reference frequency (20), integrating (30) the frequency differences to average the differences, and adjusting (40) the reference frequency (80) to eliminate the frequency difference. It is further characterized by digitizing, in quadrature, the received pure sine wave (70), mixing (50) the received pure sine wave with a complex sinusoid to translate the pure sine wave to baseband, quadrature filtering (60) the mixed sine wave, cross-product discrimination (20) to detect frequency differences between a received pure sine wave and a reference frequency, integration (30) the frequency differences to average the differences, selectively (100/110) calculating the mean/variance (90) between the pure sine wave and the reference frequency, and adjusting (40) the reference frequency of a Voltage Controlled Oscillator 80 to eliminate the frequency difference.

公开(公告)号：DD292788A5

公开(公告)日：1991-08-08

申请号：DD33574089

申请日：1989-12-15

Applicant: MOTOROLA INC

Inventor： BORTH DAVID E ,  KEPLER JAMES F M

IPC: H04L27/14 ,  H04L27/00 ,  H04L27/18 ,  H04L27/227 ,  H03J7/02

Abstract: There is provided a method of and apparatus for Automatic Frequency Control (AFC) in the presence of data. It comprises removing the effects of data modulated onto the carrier (25), detecting the frequency difference between the carrier frequency and the phase of the reference oscillator (30), and adjusting (80) the frequency of the reference oscillator (35) to eliminate the frequency difference ( DELTA ). It is further characterized by digitizing (40) the modulated carrier in quadrature, sampling (20) the modulated carrier in quadrature at a multiple of the modulated bit rate, rotating phases toward arctangent (I/Q)=0 (25/55/60) to remove the effects of quadrature data (I/Q) modulated onto the carrier, detecting (30) the frequency difference ( DELTA ) between the carrier frequency and the frequency of a Voltage Controlled type of reference oscillator (35) with a phase trajectory estimator (45), and establishing and generating the requisite correction voltage ( DELTA ) for a Voltage Controlled type of reference oscillator (VCO) (35) with the phase trajectory estimator (45).

公开(公告)号：DD292787A5

公开(公告)日：1991-08-08

申请号：DD33499989

申请日：1989-11-29

Applicant: MOTOROLA INC

Inventor： KEPLER JAMES F M ,  BORTH DAVID E ,  CERNY FRANK I JR

IPC: H03G3/20 ,  H04B3/06 ,  H04B7/005 ,  H04B7/26 ,  H04J3/00 ,  H04J3/16 ,  H04L27/18 ,  H04L27/22 ,  H04L27/38 ,  H03G3/00

Abstract: There is provided a method of digital Automatic Gain Control (AGC) in a receiver having limited dynamic range, particularly for discontinuous signals. The method is characterized by detecting the level of a received and AGC'd discontinuous signal, comparing the level of the AGC'd signal relative to the dynamic range of the receiver, and adjusting the AGC to establish a desired relationship between the AGC'd signal and the dynamic range limitation. There is also provided a method of handoff in a TDMA cellular-type transmission system utilizing this method of AGControl. The method for Automatic Gain Control (AGC) of discontinuous signals in a receiver having limited dynamic range is further characterized by: digitizing (A/D) a received and AGC'd discontinuous signal and converting the digitized samples to a power sample to sense the power of and detect the level of the signal, comparing the level of the AGC'd signal relative to the dynamic range of the receiver; and coarsely-adjusting by either progressively attenuating the signal until it falls within the dynamic range of the receiver or by progressively gain-amplifying the signal until it falls within the limited dynamic range of the receiver and finely-adjusting the AGC of the received signal until optimum use of the full (albeit limited) dynamic range of the signal processing stages is about 6-12 dB below maximum to establish a desired relationship between the AGC'd signal and the dynamic range limitation.