Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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 (116, 118) and a second set of synchronized signals (120, 122), 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 (116, 118) and the second set of synchronized signals (120, 122) to obtain an in-phase intermediate frequency (IF) signal (132) and a quadrature-phase IF signal (142), respectively.

Abstract: 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 (116, 118) and a second set of synchronized signals (120, 122), 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 (116, 118) and the second set of synchronized signals (120, 122) to obtain an in-phase intermediate frequency (IF) signal (132) and a quadrature-phase IF signal (142), respectively.

Abstract: 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.

Abstract: A mobile subscriber unit (102) transmits a signal including vocoder voices frames to a base unit (104) within a communication system (100). The base unit (104) repeats the signal including error information from the voice frames to one or more final recipient unit(s). The originating subscriber unit (102) listens to these error mitigated repeated frames and compares the received signal having error information to voice frame conditions, such as calculated, delayed and muted signal patterns. Based on the comparison, the subscriber unit (102) adjusts its power accordingly.

Abstract: 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.

Abstract: A digital receiver fast frequency and time acquisition system (200) 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 (204) that filters an incoming digital signal (202). A frame synchronization detector (206) then recognizes the time synchronization word from the first filtered signal. A coarse symbol time estimator (208) is then used for coarsely adjusting the time synchronization of the digital signal from the frame synchronization detector (206) and a fine frequency estimator (210) finely adjusts the frequency of the signal from the coarse symbol time estimator (208) for providing a frequency adjusted signal. A mixer (212) then combines the incoming digital signal with the frequency adjusted signal and provides a time and frequency compensated digital signal.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method for suppressing a carrier in a quadrature modulator includes applying a first set of four correction signal pairs to a quadrature modulator and detecting a first set of four output signals, identifying a first optimum correction signal pair among the first set of four correction signal pairs, and applying the first optimum correction signal pair to the quadrature modulator for suppressing a carrier. An apparatus for suppressing a carrier in a quadrature modulator includes an amplifier, a radio frequency detector coupled to the amplifier, an analog-to-digital converter coupled to the radio frequency detector, a correction circuit coupled to the analog-to-digital converter; the correction circuit performing a search algorithm during a training period and determining a pair of channel correction values for suppressing a carrier; and a pair of summers coupled to the correction circuit.

Abstract: 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.

Abstract: A digital receiver fast frequency and time acquisition system (200) 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 (204) that filters an incoming digital signal (202). A frame synchronization detector (206) then recognizes the time synchronization word from the first filtered signal. A coarse symbol time estimator (208) is then used for coarsely adjusting the time synchronization of the digital signal from the frame synchronization detector (206) and a fine frequency estimator (210) finely adjusts the frequency of the signal from the coarse symbol time estimator (208) for providing a frequency adjusted signal. A mixer (212) then combines the incoming digital signal with the frequency adjusted signal and provides a time and frequency compensated digital signal.

Abstract: 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.