The present invention pertains to systems and methods for equalizing a digitally modulated input signal for transmission as an optical signal over an optical fiber. In detail, this equalization is accomplished prior to the signal's conversion to an optical signal, and prior to the signal being filtered by a vestigial sideband (VSB) filter. In particular, equalization is accomplished by giving weights to the taps of a tapped delay equalizer, wherein weights for respective taps are derived from the output signal after its conversion to a digital signal at the downstream end of the optical fiber.

Disclosed herein are a gateway-signaling method for Multiple-Input Single-Output (MISO) operation and an apparatus for the same. An apparatus for transmitting a broadcast signal according to an embodiment of the present invention includes a predistortion unit for performing predistortion for decorrelating signals corresponding to transmitters using the number of transmitters used for MISO and a transmitter coefficient index that are identified using a timing and management packet transmitted through a Studio-to-Transmitter Link (STL), thereby generating a pre-distorted signal; and an RF signal generation unit for generating an RF transmission signal using the pre-distorted signal corresponding to the transmitter coefficient index.

An apparatus for interpolation of polar signals in RF transmitters is disclosed. The apparatus comprises an estimation circuit configured to receive an input in-phase (I) quadrature (Q) signal comprising a plurality of input IQ samples having a first sampling rate associated therewith, and determine a selection metric value indicative of a position of an IQ trajectory associated with one or more input IQ samples of the input IQ signal. The apparatus further comprises a selection circuit configured to receive the input IQ signal and the selection metric value; and adaptively provide the input IQ signal to a first interpolation circuit that implements a first interpolation method or to a second interpolation circuit that implements a second, different interpolation method, for generating interpolated polar samples at a second, different sampling rate, from the input IQ signal, based on the selection metric value.

A radio transmission device for the radio transmission of an interrogation signal based on a signal to be amplified is provided. This method comprises a generator for generating a signal to be amplified, and a selection block for selecting a type of interrogation signal to be transmitted from among at least two different types of signals. The generator for generating a signal to be amplified is configured so as to allow transmission of the signal to be amplified so as to generate the interrogation signal corresponding to the selected type of interrogation signal.

An apparatus for transmitting output signals includes a pre-distortion circuit configured to perform digital pre-distortion (DPD) on input signal samples using a plurality of DPD coefficients to generate a plurality of pre-distorted samples. The apparatus further includes an estimation window search circuit configured to determine a signal power characteristic for each pre-distorted sample of the plurality of pre-distorted samples, and select a subset of the plurality of pre-distorted samples based on the determined signal power characteristics. The subset of the plurality of pre-distorted samples is selected to fit within a predetermined estimation window size. The plurality of DPD coefficients is updated based on the subset of the plurality of pre-distorted samples.

A wireless transceiver. The transceiver includes: (i) a transmit signal path; (ii) a calibration path, comprising a conductor to connect a calibration tone into the transmit signal path; (iii) a receive signal path, comprising a first data signal path to process a first data and a second data signal path, different than the first data signal path, to process a second data; (iv) a first capacitive coupling to couple a response to the calibration tone from the transmit signal path to the first data signal path; and (v) a second capacitive coupling to couple a response to the calibration tone from the transmit signal path to the second data signal path.

Various embodiments of the present disclosure relate to transmitter systems, methods, and instructions for signal predistortion. The transmitter system includes a signal decomposition module configured to extract a low-frequency signal (S.sub.lo) and a high-frequency signal (S.sub.hi) from an input signal (S.sub.in); a distortion compensation processing module configured to generate a pre-distorted low-frequency signal (U.sub.lo) and a pre-distorted high-frequency signal (U.sub.hi) based on the received low-frequency and high-frequency signals using signal generation coefficients; a signal combining module configured to combine the pre-distorted low-frequency signal (U.sub.lo) and the pre-distorted high-frequency signal (U.sub.hi); and a signal characteristic estimation processing module configured to update the signal generation coefficients used by the distortion compensation processing module based on comparing the low-frequency signal (S.sub.lo) and the high-frequency signal (S.sub.hi) with a detected feedback low-frequency signal (Y.sub.lo) and a detected feedback high-frequency signal (Y.sub.hi).

A wireless communications system includes a pre-distortion actuator configured to receive a carrier-modulated signal and convert the carrier-modulated signal into an output signal, the pre-distortion actuator comprising a behavioral model that models a transmit chain of the system including at least one amplifier and at least one antenna and predict an input-output relationship of the transmit chain of the system between an input to the transmit chain to an output of the transmit chain. The system includes a phased antenna array configured to transmit the output signal. The phased antenna array includes a plurality of antenna elements, each antenna element electrically coupled to a respective power amplifier. The pre-distortion actuator is configured to generate the output signal by applying a correction to the carrier-modulated input signal that cancels out nonlinearities The behavioral model is updated based on feedback from a receiver from a previous output signal transmitted to the receiver.

A method for controlling a combined waveform, representing a combination of at least two signals having orthogonal frequency multiplexed signal components, comprising: receiving information defining the at least two signals; transforming the information defining each signal to a representation having orthogonal frequency multiplexed signal components, such that at least one signal has at least two alternate representations of the same information, and combining the transformed information using the at least two alternate representations, in at least two different ways, to define respectively different combinations; analyzing the respectively different combinations with respect to at least one criterion; and outputting a respective combined waveform or information defining the waveform, representing a selected combination of the transformed information from each of the at least two signals selected based on the analysis.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a wireless node may receive a configuration indicating a parameter of a signal to be optimized for a portion of a frequency range. The wireless node may transform a feedback signal and a reference signal into a frequency domain. The wireless node may generate an error signal based at least in part on transforming the feedback signal and the reference signal. The wireless node may assign weights to the error signal to generate a weighted error signal. The weights may be assigned to the error signal in the portion of the frequency range and a remaining portion of the frequency range according to the configuration. The wireless node may transmit the signal based at least in part on utilizing the weighted error signal to apply digital pre-distortion to the signal. Numerous other aspects are described.