Motorola Corporation

Freescale Semiconductor,inc.

Motorola Solutions, Inc.

Sumit Anil Talwalkar

Mahibur Rahman

Leng H Ooi

Vijay Nangia

Robert E Stengel

Charles LeRoy Sobchak

Nicholas Giovanni Cafaro

Geetha B Nagaraj

Charles R Ruelke

Mark Alan Kirschenmann

Steven P Hoggarth

Andrew Gerald Zocher

An improved superheterodyne receiver for a portable radio is provided. The receiver includes a frequency controller that applies pulse-shaped modulation to first and second LO signals in a synchronized manner. The frequency controller is steered by Artificial Intelligence (AI) based machine learning (ML) to determine first and second LOs that minimize image interference in the baseband signal.

Method and apparatus for mitigating image interference in a receiver

A synthesizer comprises a first processing unit that receives digital information relating to a required final frequency of the synthesizer and determines a primary frequency value and a corresponding frequency multiplier mode. A primary synthesizer receives the primary frequency value and an external reference frequency signal to generate a signal of the primary frequency. The synthesizer further comprises a second processing unit that receives the primary frequency value, determines a pre-charge voltage value corresponding to the primary frequency value, and transmits the pre-charge voltage value to a delay locked loop in response to a change in the primary frequency value. The delay locked loop receives the signal of primary frequency and the pre-charge value. The DLL is pre-charged to the pre-charge voltage value for a predetermined time, by opening and closing the delay locked loop to obtain fast locking of the synthesizer.

Method and apparatus for fast frequency locking in a closed loop based frequency synthesizer

A method and apparatus for processing a radio frequency (RF) signal is provided. The method includes generating a periodic square wave local oscillator (LO) signal of a first phase, a periodic square wave LO signal of a second phase, and a chopping signal. The method further includes coding the periodic square wave LO signal of the first phase and the periodic square wave LO signal of the second phase synchronously with the chopping signal to generate a first set of synchronized signals () and a second set of synchronized signals (), respectively. A phase difference between the first phase and the second phase is a predefined value. The RF signal is processed with the first set of synchronized signals () and the second set of synchronized signals () to obtain an in-phase intermediate frequency (IF) signal () and a quadrature-phase IF signal (), respectively.

Method and apparatus for processing radio frequency signals

A method includes performing a search method to determine a pair of receiver path correction signals, performing the search method to determine a pair of transmitter path correction signals, and using the pairs of receiver path and transmitter path correction signals to suppress a carrier signal. An apparatus includes a first pair of summers, an upconverter circuit coupled to the first pair of summers, a multiplexer coupled to the upconverter circuit, to a ground, and to an RF front end, a downconverter circuit coupled to the multiplexer, a second pair of summers coupled to the downconverter circuit, and a correction circuit coupled to the first and second pairs of summers.

Method and apparatus for RF carrier feedthrough suppression

A transmit path correction system () for compensating for digital DC offsets, I/Q gain imbalances and I/Q phase imbalances includes a mixed signal forward path () and a mixed signal feedback path (). The forward pat (), which is operable to process input data symbols to produce at least one analog output signal, preferably includes a digital DC offset correction circuit () for compensating for digital DC offsets in the forward path () using at least one digital feedback signal (), an I/Q phase equalization circuit () for compensating for the I/Q phase imbalances in the forward path (), and an I/Q gain equalization circuit () for compensating for the I/Q gain imbalances in the forward path () using the digital feedback signal(s) (). The feedback pat () processes the analog output of the forward path () to produce the digital feedback signal(s) ().

Self calibrating transmit path correction system

A signal processing apparatus preferably suitable for implementation as an integrated circuit, that is arranged and constructed to be shared for processing a plurality of signals without interference between the signals and method thereof, the signal processing apparatus comprising: an input multiplexer for sequentially selecting from among the plurality of signals to provide a sequence of selected signals; a processing unit for processing the sequence of selected signals to provide a sequence of processed signals, the processing unit having an input coupled to the input multiplexer and a delay stage including a plurality of series coupled delay elements with one delay element corresponding to each of the plurality of signals; and an output de-multiplexer for sequentially selecting from the sequence of processed signals to provide a plurality of processed signals corresponding one to one with the plurality of signals.

Method and apparatus for shared processing a plurality of signals

A method and system controls transmit power by combining the advantages of digital attenuation and analog baseband step attenuators by calibration to overcome the limitations of analog step attenuators. The calibration technique uses highly accurate digital attenuators to determine the actual sizes of the analog steps as analog step attenuator is stepped through a range of attenuation levels. A method of calibration accurately measures attenuation steps comparison to a digital attenuator so that the attenuation actually realized by the analog step attenuator is accurately known. Therefore, the difference between the attenuation realized by the analog step attenuator and the desired attenuation is accurately known. The difference is realized in the digital attenuator and the attenuation resulting from the composite of the digital and analog step attenuator can very accurately realize the requested attenuation.

Method and apparatus for a high performance and high dynamic range baseband power control system

A digital receiver fast frequency and time acquisition system () for accurately providing both time and frequency synchronization to an incoming data stream with minimal delay to prevent any loss of incoming digital information. The invention provides synchronization with only a single synchronization word and includes a first channel select (CS) filter () that filters an incoming digital signal (). A frame synchronization detector () then recognizes the time synchronization word from the first filtered signal. A coarse symbol time estimator () is then used for coarsely adjusting the time synchronization of the digital signal from the frame synchronization detector () and a fine frequency estimator () finely adjusts the frequency of the signal from the coarse symbol time estimator () for providing a frequency adjusted signal. A mixer () then combines the incoming digital signal with the frequency adjusted signal and provides a time and frequency compensated digital signal. A second CS filter () filters the frequency compensated digital signal and a fine symbol time estimator () works to determine symbol timing with greater precision. Finally, a symbol detector () is used for interpreting the incoming digital signal.

Digital receiver fast frequency and time acquisition system using a single synchronization word and method of using same

Systems and methods are described for a sideband suppression technique for quadrature modulation using magnitude measurements. Gain imbalance, phase imbalance, or both gain and phase imbalance are corrected in a quadrature modulator. Predetermined voltage levels are applied to one or both of the quadrature modulator input channels and resultant output magnitudes are measured. Then, a gain correction factor, a phase correction factor or both gain and a phase correction factors are determined as a function of the measured output magnitudes. Gain imbalance, phase imbalance or both gain and imbalance are then corrected using the gain and phase correction factors.

Sideband suppression method and apparatus for quadrature modulator using magnitude measurements

A system and method are disclosed to provide increased signaling in a communications system. A repeater system is operable to receive and store operating characteristic data from a communications unit, the repeater transmitting at least some of the stored operating characteristic data during a detected break in transmission.

Intelligent repeater and method to provide increased signaling

A null-pilot symbol assisted fast automatic frequency control (AFC) system for coherent demodulation of carrier phase modulation (CPM) includes ( ) a pilot clock driven phase differentiator ( ) for operating once every pilot clock cycle to determine the difference between the phase at a current pilot symbol location and the phase at a previous pilot symbol location. A frequency offset selector ( ) is then used for choosing the most likely frequency offset from amongst a set of all frequency offsets that give rise to the same phase difference.

Null-pilot symbol assisted fast automatic frequency control (AFC) system for coherent demodulation of continuous phase modulation (CPM) signals and method for implementing same

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Plantation, FL, United States of America

Sumit Anil Talwalkar