Abstract:
A radio frequency (RF) receiver and method of controlling an RF receiver are provided. The method includes receiving an RF signal and down-converting the RF signal to a substantially baseband signal. A direct current (DC) transition is detected in a portion of the substantially baseband signal. The substantially baseband signal is then filtered using a first filter configuration at the portion of the substantially baseband signal including the DC transition and a second filter configuration at a portion of the substantially baseband signal not including the DC transition.
Abstract:
Methods and systems for evaluating compliance of communication of a dispatcher. One system includes an electronic computing device that includes an input device, a transceiver, and one or more electronic processors. The one or more electronic processors are configured to monitor communication between a dispatcher and a caller during a call and determine a type of call. The one or more electronic processors are further configured to determine a conversational procedure based on the type of call and compare a characteristic of the monitored communication to a constraint of the conversational procedure. The one or more electronic processors are further configured to determine that the characteristic of the monitored communication is outside the constraint of the conversational procedure and take an action as a function of determining that the characteristic of the monitored communication is outside the constraint of the conversational procedure.
Abstract:
Portable communications device and method for full duplex operation in a time division multiple access radio system. The method includes providing a switch for connecting one of a first voltage controlled oscillator and a second voltage controlled oscillator to a synthesizer. The synthesizer generates a first frequency when connected to the first voltage controlled oscillator and generates a second frequency when connected to the second voltage controlled oscillator. The method also includes controlling, using an electronic processor coupled to the switch, the switch to connect the first voltage controlled oscillator to the synthesizer for a first timeslot, and controlling, using the electronic processor, the switch to disconnect the first voltage controlled oscillator from the synthesizer and connect the second voltage controlled oscillator to the synthesizer for a second timeslot. The second timeslot is immediately adjacent to the first timeslot.
Abstract:
Portable communications device and method for full duplex operation in a time division multiple access radio system. The method includes providing a switch for connecting one of a first voltage controlled oscillator and a second voltage controlled oscillator to a synthesizer. The synthesizer generates a first frequency when connected to the first voltage controlled oscillator and generates a second frequency when connected to the second voltage controlled oscillator. The method also includes controlling, using an electronic processor coupled to the switch, the switch to connect the first voltage controlled oscillator to the synthesizer for a first timeslot, and controlling, using the electronic processor, the switch to disconnect the first voltage controlled oscillator from the synthesizer and connect the second voltage controlled oscillator to the synthesizer for a second timeslot. The second timeslot is immediately adjacent to the first timeslot.
Abstract:
A very low intermediate frequency (VLIF) receiver and a method of controlling a VLIF receiver. The method comprises estimating energy levels in first and second signals and detecting interference from a first adjacent channel interferer based upon a difference in energy in the first and second signals. The first signal comprising a first on-channel portion and an adjacent channel portion and the second signal comprises an intermediate frequency translation of the first on-channel portion. The energy levels are estimated for corresponding time instances and the adjacent channel interferer is of the adjacent channel portion. The VLIF receiver is then controlled based upon the detected interference.
Abstract:
A very low intermediate frequency (VLIF) receiver and a method of controlling a VLIF receiver. The method comprises estimating energy levels in first and second signals and detecting interference from a first adjacent channel interferer based upon a difference in energy in the first and second signals. The first signal comprising a first on-channel portion and an adjacent channel portion and the second signal comprises an intermediate frequency translation of the first on-channel portion. The energy levels are estimated for corresponding time instances and the adjacent channel interferer is of the adjacent channel portion. The VLIF receiver is then controlled based upon the detected interference.
Abstract:
An apparatus and method for reducing FM audio artifacts in a receiver are provided. A direct conversion radio frequency (RF) receiver converts an analog FM signal into a phase shifted digital low IF signal. A digital controller coupled to the analog FM receiver provides adaptive frequency translation for different channel spacing and provides adaptive low IF configuration through the different channel spacing, thereby suppressing audio artifacts.