摘要:
Embodiments include methods and apparatus for detecting a phase angle between an incident signal and a reflected signal. The apparatus comprises a plurality of phase shifters and additional circuitry. The plurality of phase shifters is adapted to apply first phase shifts to a representation of the incident signal and to apply second phase shifts to a representation of the reflected signal. The additional circuitry, which is operatively coupled to the plurality of phase shifters, is adapted to produce a first indication of a location of a relative phase difference between the incident signal and the reflected signal within a first region of a first reference circle, and to produce a second indication of the location of the relative phase difference within a second region of a second reference circle, wherein the second reference circle is rotated with respect to the first reference circle.
摘要:
A system (100, FIG. 1) performs digital pre-distortion using gain values stored in a lookup table (150). A method for performing digital pre-distortion includes identifying (310, FIG. 3) a lookup table entry, based on input data, and updating the lookup table entry by writing an updated gain value into the lookup table entry. In an embodiment, update tracking information corresponding to the lookup table entry may be updated (324) to indicate that the lookup table entry has been updated. Another embodiment includes identifying (412, FIG. 4) consecutive lookup table entries based on input data, determining (413) whether the consecutive lookup table entries have been previously updated, and performing (414) a weighted interpolation process to produce an output gain value. A previous gain value (158, FIG. 1) is used in the weighted interpolation process when at least one of the consecutive lookup table entries has not been updated.
摘要:
A soft saturation detection circuit for a radio frequency (“RF”) power amplifier is configured to detect the onset of soft saturation in an unambiguous and accurate manner. The circuit compares the time derivative of a voltage signal indicative of the RF output power to the time derivative of a control voltage signal for the RF power amplifier. The circuit also employs a gating mechanism that ensures that a soft saturation indication signal is generated under appropriate operating conditions.
摘要:
A method and amplifier circuit (20) for conditioning a signal. The amplifier circuit (20) includes a field effect transistor (22) having a sub-harmonic termination (21) connected to a drain of the field effect transistor (22). In addition, an output impedance termination (24) is connected to the drain of the field effect transistor (22) and an input impedance termination (23) is connected to the gate of the field effect transistor (22). The sub-harmonic termination (21) reduces a non-linear component of an interference signal.
摘要:
In accordance with some embodiments of the present disclosure, a method may include determining a range of frequencies allocated to resource blocks to be transmitted during a subsequent sub-frame slot or sounding reference symbol sub-slot. The method may also include determining an approximate center frequency of the range of frequencies. The method may additionally include modulating resource blocks of the sub-frame or sounding reference symbol sub-slot at the approximate center frequency. The method may further include transmitting the modulated resource blocks at the approximate center frequency.
摘要:
Embodiments include methods and apparatus for detecting a phase angle between an incident signal and a reflected signal. The apparatus comprises a plurality of phase shifters and additional circuitry. The plurality of phase shifters is adapted to apply first phase shifts to a representation of the incident signal and to apply second phase shifts to a representation of the reflected signal. The additional circuitry, which is operatively coupled to the plurality of phase shifters, is adapted to produce a first indication of a location of a relative phase difference between the incident signal and the reflected signal within a first region of a first reference circle, and to produce a second indication of the location of the relative phase difference within a second region of a second reference circle, wherein the second reference circle is rotated with respect to the first reference circle.
摘要:
A system (100, FIG. 1) performs digital pre-distortion using gain values stored in a lookup table (150). A method for performing digital pre-distortion includes identifying (310, FIG. 3) a lookup table entry, based on input data, and updating the lookup table entry by writing an updated gain value into the lookup table entry. In an embodiment, update tracking information corresponding to the lookup table entry may be updated (324) to indicate that the lookup table entry has been updated. Another embodiment includes identifying (412, FIG. 4) consecutive lookup table entries based on input data, determining (413) whether the consecutive lookup table entries have been previously updated, and performing (414) a weighted interpolation process to produce an output gain value. A previous gain value (158, FIG. 1) is used in the weighted interpolation process when at least one of the consecutive lookup table entries has not been updated.
摘要:
Embodiments include methods, apparatus, and electronic systems adapted to perform adaptive pre-distortion. Embodiments include combining an input sample with a gain value to generate a pre-distorted data sample, where the gain value is a function of at least one gain entry stored within a gain lookup table. An amplified analog signal is generated from the pre-distorted data sample, and a feedback sample is also generated, which corresponds to an antenna output signal. The antenna output signal includes the amplified analog signal. A difference indicator is generated to reflect a difference between the input sample and the feedback sample, and at least one updated gain value is generated based on a comparison between the difference indicator and at least one previous difference indicator. At least one gain entry within the gain lookup table is updated with the at least one updated gain value.
摘要:
A balanced power amplifier that is insensitive to load line variations is provided. The balanced power amplifier is suitable for use in wireless transmitter applications, such as cellular telephones, mobile computing devices, and portable communication devices. An embodiment of such a balanced power amplifier includes an input coupler, first and second amplifier devices, and a level adjustment component. The input coupler generates a first signal component and a second signal component from an input signal, where the first signal component and the second signal component are out of phase relative to one another. The first amplifier device generates a first output signal that is influenced by the first signal component, and the second amplifier device generates a second output signal that is influenced by the second signal component. The level adjustment component is coupled between the input coupler device and the input of the first amplifier device. The level adjustment component performs signal level tuning on its input signal. The signal level tuning is adaptively performed in response to the impedance characteristics of the load being driven by the balanced power amplifier.
摘要:
Embodiments include methods, apparatus, and electronic systems adapted to perform adaptive pre-distortion. Embodiments include combining an input sample with a gain value to generate a pre-distorted data sample, where the gain value is a function of at least one gain entry stored within a gain lookup table. An amplified analog signal is generated from the pre-distorted data sample, and a feedback sample is also generated, which corresponds to an antenna output signal. The antenna output signal includes the amplified analog signal. A difference indicator is generated to reflect a difference between the input sample and the feedback sample, and at least one updated gain value is generated based on a comparison between the difference indicator and at least one previous difference indicator. At least one gain entry within the gain lookup table is updated with the at least one updated gain value.