摘要:
A system and method for heartbeat signal generation are provided. The method includes determining a communication condition and generating heartbeat signals based on the determined communication condition. The system includes a plurality of communication cells and at least one communication device configured to generate heartbeat signals. A rate of generating the heartbeat signals is based on one of (i) a service priority or user group and (ii) communication requirements for a network type for each of the plurality of communication cells.
摘要:
A system and method for providing land mobile radio (LMR) content using a cellular data network is provided. The method includes communicating the LMR content via at least one of an LMR network and a cellular data network. The method further includes encapsulating the LMR content using a packet switching protocol when communicating the LMR content via the cellular data network.
摘要:
A multimode land mobile radio (LMR) and a method of communicating land mobile radio (LMR) content using an LMR device are provided. The LMR includes an LMR communication portion configured to provide communication with an LMR network and a cellular data network communication portion configured to provide communication with a cellular data network.
摘要:
A system and method for modulating and amplifying an input signal are provided in a communication transmitter. The transmitter includes a pre-distortion lookup table containing pre-distortion lookup data. An auto-calibration module is in communication with the pre-distortion lookup table. The auto-calibration module is configured to operate during a closed-loop auto-calibration interval and to calibrate the pre-distortion lookup data to compensate for a non-linearity in the transmitter. The pre-distortion is based on the pre-distortion lookup data and is used during an open-loop operational interval.
摘要:
A wireless communication system may include a first base station having a first communication coverage area and operating in an HFDD mode using a first frequency and a second frequency in an alternating pattern. The system may also include a second base station having a second communication coverage area different than the first communication coverage area and also operating in an HFDD mode. The second base station may communicate using the first frequency and the second frequency in an opposite alternating pattern from the first base station.
摘要:
A wireless communication network is provided that includes a plurality of communication cells each defined by at least one communication coverage area and a plurality of access points each corresponding to a different one of the plurality of communication cells. Each access point is configured to communicate on a first frequency with at least one of (i) a subscriber in the at least one communication coverage area in a first communication cell and (ii) a subscriber in a second communication cell. Each access point is further configured to communicate on a second frequency with an access point in a third communication cell.
摘要:
A method and apparatus for a nonlinear feedback control system is disclosed, such as for electrical and electronic systems, for pre-distorting a nonlinear device. A nonlinear feedback control system includes a nonlinear device having a first input and a first output. A detection stage is in communication with the first output of the nonlinear device. A derivation stage is in communication with the detection stage, and the derivation stage is in communication with the first input of the nonlinear device.
摘要:
A method for generating a modulated carrier signal with reduced bit error rates based on a plurality of data symbols. A plurality of data symbols are received, and a digital input signal is generated based on the plurality of data symbols. The digital input signal are filtered to produce a digital output signal including a phase characteristic. The phase characteristic of the digital output signal remains close to the desired symbol phase for substantial portion of the symbol period. A carrier signal is modulated using the digital output signal to produce the modulated carrier signal.
摘要:
A security system for a digital trunked radio system having a digital control channel and a plurality of working channels, wherein said working channels are assigned for temporary use of individual radio units by digital control signals transmitted over said control channel, said control channel carrying digital control signals between a base site and said radio units, comprising a digital key, said key used to limit access to the system equipment and system control channel transmissions.
摘要:
An apparatus and method for characterizing an amplifier transmitting a band limited signal using a sample of the input signal to the amplifier and a sample of the output signal from the amplifier, where the output signal is sub-sampled. The sub-sampling frequency is chosen such that images of the band limited signal do not overlap. The input signal and the output signal in a polar format are processed to determine characteristics such AM/AM and AM/PM conversion nonlinearities.