-
公开(公告)号:FI980592A
公开(公告)日:1998-03-18
申请号:FI980592
申请日:1998-03-17
Applicant: QUALCOMM INC
Inventor: WILSON NATHANIEL B
Abstract: The present invention provides linear, digital automatic gain control (AGC) in a radio. A received signal is demodulated to provide I and Q digital baseband signals. A received signal strength indication is determined from these signals and the resulting digital signal is adjusted to provide a logarithmic response. This signal is then integrated to provide a digital receive AGC adjust signal. For the transmit AGC adjust, the digital receive AGC adjust signal is filtered and then summed with a scaled closed loop power control command. The closed loop power control commands are ignored if they would result in increasing the transmit gain beyond the amplifier's designed maximum output. The result of the sum operation converted from digital to analog for adjusting the amplifier. The outputs of the transmit and receive AGC amplifiers are linearized by transmit and receive linearizers, respectively, which pre-distort the digital AGC adjust signals prior to digital to analog conversion.
-
公开(公告)号:FI972590A
公开(公告)日:1997-08-25
申请号:FI972590
申请日:1997-06-17
Applicant: QUALCOMM INC
Inventor: BLACK PETER J , WILSON NATHANIEL B
IPC: H04L27/10 , H04B1/04 , H04B1/40 , H04B7/26 , H04L25/49 , H04L27/14 , H04L27/233 , H04W4/18 , H04W88/06 , H04B , H04J
Abstract: A dual-mode digital communication system for communicating an information signal during operation in frequency-modulated (FM) and multiple-access modes is disclosed herein. The digital communication system includes a dual-mode transmitter for transmitting the information signal using an FM communication signal during FM mode operation, and for transmitting the information signal using a multiple-access communication signal during multiple-access mode operation. The communication system further includes a dual-mode receiver for receiving the FM communication signal during FM mode operation, and for receiving the multiple-access communication signal during multiple-access mode operation. Incorporated within the dual-mode receiver is a digital demodulator for recovering the information signal from the received FM signal during operation in the FM mode, and for recovering the information signal from the received multiple-access signal during multiple-access mode operation. In a preferred implementation the dual-mode transmitter is disposed to convert a first sequence of binary data within the information signal into a sampled modulation waveform, and to provide the FM communication signal by modulating a carrier signal based at least in part on the sampled modulation waveform. The dual-mode transmitter may also be configured to multiplex a second sequence of wideband message data with the sampled modulation waveform so as to form a composite FM modulation waveform.
-
公开(公告)号:AU7160996A
公开(公告)日:1997-04-01
申请号:AU7160996
申请日:1996-09-16
Applicant: QUALCOMM INC
Inventor: WILSON NATHANIEL B
Abstract: The present invention provides linear, digital automatic gain control (AGC) in a radio. A received signal is demodulated to provide I and Q digital baseband signals. A received signal strength indication is determined from these signals and the resulting digital signal is adjusted to provide a logarithmic response. This signal is then integrated to provide a digital receive AGC adjust signal. For the transmit AGC adjust, the digital receive AGC adjust signal is filtered and then summed with a scaled closed loop power control command. The closed loop power control commands are ignored if they would result in increasing the transmit gain beyond the amplifier's designed maximum output. The result of the sum operation converted from digital to analog for adjusting the amplifier. The outputs of the transmit and receive AGC amplifiers are linearized by transmit and receive linearizers, respectively, which pre-distort the digital AGC adjust signals prior to digital to analog conversion.
-
公开(公告)号:ZA9607426B
公开(公告)日:1997-03-10
申请号:ZA9607426
申请日:1996-09-02
Applicant: QUALCOMM INC
Inventor: WILSON NATHANIEL B
CPC classification number: H03G3/3042 , H03F1/3241 , H03F2200/294 , H03F2200/372
-
公开(公告)号:BR9506205A
公开(公告)日:1996-04-23
申请号:BR9506205
申请日:1995-04-28
Applicant: QUALCOMM INC
Inventor: WILSON NATHANIEL B , BLACK PETER J , PETERZELL PAUL E
Abstract: An automatic gain control (AGC) and D.C. offset correction method and apparatus for controlling signal power of a received RF signal within a dual mode quadrature receiver is disclosed herein. In a preferred implementation the automatic gain control apparatus may be adjusted to provide a desired control response to various fading characteristics of a received FM, FSK, GMSK, QPSK, or BPSK signal. The AGC apparatus includes an adjustable gain amplifier having an input port for receiving an input signal, a control port for receiving a gain control signal, and an output port for providing an output signal. A quadrature downconverter coupled to the output port serves to translate the frequency of the output signal to a baseband frequency, thereby producing baseband signals. In a preferred implementation the downconverter is operative to map the carrier frequency of the output signal to a baseband frequency offset by a predetermined margin from D.C. Two high gain active lowpass filters provide out-of-band signal rejection for the baseband signals. A D.C. feedthrough suppression loop, disposed to receive said baseband signal, suppresses D.C. offsets produced by the downconverter and lowpass filters, hence providing a compensated baseband signal. The AGC apparatus is further disposed to generate a received power signal based on the power of the output signal. A saturating integrator compares the received power signal to a reference signal and produces the gain control signal by integrating or by refraining from integration based on values of the reference, received power signal, and gain control signals, thereby extending the usable dynamic range of the receiver for FM mode.
-
公开(公告)号:ZA9503124B
公开(公告)日:1996-04-02
申请号:ZA9503124
申请日:1995-04-18
Applicant: QUALCOMM INC
Inventor: PETERZELL PAUL E , WILSON NATHANIEL B , BLACK PETER J
CPC classification number: H03G3/3078 , H03G3/3089
-
公开(公告)号:FI956286A0
公开(公告)日:1995-12-27
申请号:FI956286
申请日:1995-12-27
Applicant: QUALCOMM INC
Inventor: WILSON NATHANIEL B , BLACK PETER J , PETERZELL PAUL E
Abstract: An automatic gain control (AGC) and D.C. offset correction method and apparatus for controlling signal power of a received RF signal within a dual mode quadrature receiver is disclosed herein. In a preferred implementation the automatic gain control apparatus may be adjusted to provide a desired control response to various fading characteristics of a received FM, FSK, GMSK, QPSK, or BPSK signal. The AGC apparatus includes an adjustable gain amplifier having an input port for receiving an input signal, a control port for receiving a gain control signal, and an output port for providing an output signal. A quadrature downconverter coupled to the output port serves to translate the frequency of the output signal to a baseband frequency, thereby producing baseband signals. In a preferred implementation the downconverter is operative to map the carrier frequency of the output signal to a baseband frequency offset by a predetermined margin from D.C. Two high gain active lowpass filters provide out-of-band signal rejection for the baseband signals. A D.C. feedthrough suppression loop, disposed to receive said baseband signal, suppresses D.C. offsets produced by the downconverter and lowpass filters, hence providing a compensated baseband signal. The AGC apparatus is further disposed to generate a received power signal based on the power of the output signal. A saturating integrator compares the received power signal to a reference signal and produces the gain control signal by integrating or by refraining from integration based on values of the reference, received power signal, and gain control signals, thereby extending the usable dynamic range of the receiver for FM mode.
-
公开(公告)号:FI955072A
公开(公告)日:1995-12-22
申请号:FI955072
申请日:1995-10-25
Applicant: QUALCOMM INC
Inventor: WEILAND ANA L , KORNFELD RICHARD K , KERR RICHARD J , MALONEY JOHN E , WILSON NATHANIEL B
Abstract: The process and apparatus of the present invention limits the output power of a radiotelephone, operating in a cellular system in the preferred embodiment. This ensures the transmitted sidebands and synthesizer phase noise remains within a certain specification. This is accomplished by power detection and a correction accumulator that together generate a gain control signal by limiting the gain adjustment to a maximum value, even when the cell site communicating with the radiotelephone is sending power turn-up commands to the radiotelephone. This process includes dynamically correcting the output level of the transmitter due to gain variations in the transmitter stages or gain control elements.
-
69.
公开(公告)号:ZA9500605B
公开(公告)日:1995-12-20
申请号:ZA9500605
申请日:1995-01-25
Applicant: QUALCOMM INC
Inventor: WILSON NATHANIEL B , BLACK PETER J , PETERZELL PAUL E
IPC: H03G3/20 , H03D3/00 , H03D3/24 , H03D7/16 , H03G3/30 , H04B1/30 , H04L27/14 , H04L27/22 , H03G , H03D
CPC classification number: H03D7/165 , H03D3/002 , H03D3/008 , H03D2200/0025 , H03D2200/0047 , H03D2200/005 , H03D2200/0052 , H03G3/3052 , H03G3/3089
-
70.
公开(公告)号:AU2398995A
公开(公告)日:1995-11-29
申请号:AU2398995
申请日:1995-04-28
Applicant: QUALCOMM INC
Inventor: WILSON NATHANIEL B , BLACK PETER J , PETERZELL PAUL E
Abstract: An automatic gain control (AGC) and D.C. offset correction method and apparatus for controlling signal power of a received RF signal within a dual mode quadrature receiver is disclosed herein. In a preferred implementation the automatic gain control apparatus may be adjusted to provide a desired control response to various fading characteristics of a received FM, FSK, GMSK, QPSK, or BPSK signal. The AGC apparatus includes an adjustable gain amplifier having an input port for receiving an input signal, a control port for receiving a gain control signal, and an output port for providing an output signal. A quadrature downconverter coupled to the output port serves to translate the frequency of the output signal to a baseband frequency, thereby producing baseband signals. In a preferred implementation the downconverter is operative to map the carrier frequency of the output signal to a baseband frequency offset by a predetermined margin from D.C. Two high gain active lowpass filters provide out-of-band signal rejection for the baseband signals. A D.C. feedthrough suppression loop, disposed to receive said baseband signal, suppresses D.C. offsets produced by the downconverter and lowpass filters, hence providing a compensated baseband signal. The AGC apparatus is further disposed to generate a received power signal based on the power of the output signal. A saturating integrator compares the received power signal to a reference signal and produces the gain control signal by integrating or by refraining from integration based on values of the reference, received power signal, and gain control signals, thereby extending the usable dynamic range of the receiver for FM mode.
-
-
-
-
-
-
-
-
-