A power amplifier includes an amplifying circuit, a feedback circuit and a grounding capacitor. The amplifier circuit includes at least a first transistor and a second transistor. A control terminal of the first transistor is configured to receive an input signal, a first terminal of the second transistor is coupled to the first transistor, and a second terminal of the second transistor is configured to generate an output signal. The feedback circuit is coupled to the control terminal of the first transistor and the second terminal of the second transistor. The ground capacitor is configured to couple the control terminal of the second transistor to ground. When a frequency of the input signal is between a first band and a second band, an amplification gain of the output signal relative to the input signal is substantially the same.

Provided is a high frequency signal receiving unit that receives a first high frequency signal and that generates a first intermediate frequency signal. A packet generating unit generates a packet on the basis of the first high frequency signal. A packet output unit outputs the generated packet to a communication path. A packet receiving unit receives the packet via the communication path. A packet interpreting unit performs synchronization processing for the packet and generates a second intermediate frequency signal. A high frequency signal transmitting unit converts the second intermediate frequency signal into a second high frequency signal and transmits the second high frequency signal. A wireless receiver receives the second high frequency signal and performs positioning or time synchronization on the basis of the second high frequency signal.

Systems and methods are disclosed for utilizing frequency multiplier (FX) based transmitters to generate wideband, substantially distortion-free signals, when a transmitter operates under bandwidth constraints. A receiver is configured to acquire the feedback signal at the multiplier output. The systems and methods alleviate the bandwidth constraints of the receiver. Additionally, the invention includes a training methodology for estimating predistortion coefficients configured to operate under constrained transmitter and receiver bandwidth conditions.

Embodiments of the present disclosure are directed to systems and methods for mitigating energy transmitted on subcarriers in a communications network. For example, an operational bandwidth of an amplifier may be adjusted in real-time based on the networks current needs. A controller may communicate with a scheduler to identify which range of frequencies within an input signal received at the amplifier contain blanked PRBs and which contain active PRBs. The amplifier may then selectively amplify only the active PRB frequencies and exclude the blanked PRBs, thereby reducing residual energy transmission and interference typically caused when blanked PRBs are amplified.

Embodiments of the present disclosure are directed to systems and methods for mitigating energy transmitted on subcarriers in a communications network. For example, a signal intended for transmission can be separated and distributed to different amplifiers at the signal amplification stage. Amplifiers that correspond with regions of blanked PRBs in the signal can be selectively deactivated. In this way, energy wastage is reduced and interference is mitigated due to preventing residual energy transmission that may occur in the blanked regions even when no information is being carried in those regions of the signal.

Embodiments of the present disclosure are directed to systems and methods for mitigating energy transmitted on subcarriers in a communications network. For example, a signal intended for transmission may be allocated with blanked Physical Resource Blocks (PRBs) and non-blanked PRBs. In order to reduce residual energy transmission within the blanked PRBs, a compensating waveform that destructively interferes with the residual energy within the blanked PRBs can be generated and summed with the signal before amplification and final transmission to an intended recipient.

Embodiments of the present disclosure are directed to systems and methods for mitigating energy transmitted on subcarriers in a communications network. For example, a signal intended for transmission may be allocated with blanked Physical Resource Blocks (PRBs) and non-blanked PRBs. In order to reduce residual energy transmission within the blanked PRBs, selective filtering may be applied to a post-amplified waveform to mitigate unwanted energy introduced or exacerbated by power amplifiers in the communications network.

Methods and systems for detecting and mitigating the effects of time of flight interference of a radio frequency (RF) signal are provided. A wireless communication network may determine, based on one or more parameters being sufficiently different than a baseline value, that time of flight interference is occurring based on the undesirable propagation of a first cell's downlink signals into a second cell's coverage area. In response to the determination, the network may identify an offending base station and modify the RF transmission characteristics of the offending base station to prevent or mitigate the impact of the interference event on the RF signal's propagation.

A method and apparatus automatically switch a vehicle radio frequency. The method includes: receiving, by a first tuner, a first signal at a current frequency at which listening is being performed in a vehicle; determining whether an electric field condition of a second signal received at an alternative frequency meets a first requirement; determining whether a similarity between the first signal and the second signal meets a second requirement in response to a determination that the electric field condition of the second signal meets the first requirement; and automatically switching a reception frequency of the vehicle radio to the alternative frequency in response to a determination that the similarity between the first signal and the second signal meets the second requirement. The first requirement and the second requirement are changed in consideration of noise caused by an electric power steering system of the vehicle.