Abstract: An apparatus and method measures power of channels generated by a multiple-carrier transmitter that upconverts a plurality of baseband signals to a corresponding plurality of assigned carrier frequencies to generate an RF wideband signal. A measurement module's input interface receives a selected baseband signal and a corresponding assigned carrier frequency as well as the RF wideband signal. An undersampling component undersamples the RF wideband signal for a sampling interval to generate a plurality of measured aliased samples. A determination component determines a plurality of determined aliased samples based on the selected baseband signal upconverted to the corresponding assigned carrier frequency. A correlator correlates the plurality of measured aliased samples with the plurality of determined aliased samples to produce a correlation result.

Abstract: An apparatus and method measures power of channels generated by a multiple-carrier transmitter that upconverts a plurality of baseband signals to a corresponding plurality of assigned carrier frequencies to generate an RF wideband signal. A measurement module's input interface receives a selected baseband signal and a corresponding assigned carrier frequency as well as the RF wideband signal. An undersampling component undersamples the RF wideband signal for a sampling interval to generate a plurality of measured aliased samples. A determination component determines a plurality of determined aliased samples based on the selected baseband signal upconverted to the corresponding assigned carrier frequency. A correlator correlates the plurality of measured aliased samples with the plurality of determined aliased samples to produce a correlation result.

Abstract: Systems and methods are provided for precorrecting a constant envelope input signal. A phase precorrection component generates a precorrected input signal by applying a phase precorrection to the input signal. The applied phase correction alters an associated phase of the input signal without applying amplitude modulation to the signal. A linear distortion source applies amplitude distortion and phase distortion to the precorrected input signal. The applied phase correction mitigates the phase distortion applied by the linear distortion source.

Abstract: Systems and methods are provided for synchronizing a plurality of transmitters in a distributed transmission system. A data source generates a digital signal. A central data processing component inserts synchronization data into the digital signal. The synchronization data includes a periodic reset signal. A plurality of radio frequency transmitters each comprises a Trellis coder. At least one Trellis coder state at each Trellis coder is reinitialized to a predefined default state in response to the reset signal.

Abstract: A circuit for use in a broadcast transmitter for adaptively compensating for carrier signal distortions caused by amplitude modulating an RF carrier signal. The circuit includes a modulator/amplifier network that receives an RF carrier signal and modulates it by a received amplitude varying signal to obtain therefrom a modulated carrier signal which may exhibit distortions caused by the amplitude modulating of the RF carrier signal. A digitally adaptive corrector precorrects the amplitude varying signal prior to application thereof to the network to compensate for any modulated carrier signal distortions. This includes a digital processor that provides signal correction as a function of digital samples representing amplitude variations of the modulated RF carrier signal.

Abstract: A system and method are provided for providing nonlinear precorrection to an input signal. A plurality of nonlinear function blocks each receive a constituent signal, derived from the input signal. Each constituent signal has an associated value and an associated delay. The nonlinear function blocks output an intermediate signal having a value equal to that of an associated memoryless nonlinear function evaluated at the value of the constituent signal. A summation function sums the plurality of intermediate signals to obtain a system output.

Abstract: A circuit for use in a broadcast transmitter for adaptively compensating for carrier signal distortions caused by amplitude modulating an RF carrier signal. The circuit includes a modulator/amplifier network that receives an RF carrier signal and modulates it by a received amplitude varying signal to obtain therefrom a modulated carrier signal which may exhibit distortions caused by the amplitude modulating of the RF carrier signal. A digitally adaptive corrector precorrects the amplitude varying signal prior to application thereof to the network to compensate for any modulated carrier signal distortions. This includes a digital processor that provides signal correction as a function of digital samples representing amplitude variations of the modulated RF carrier signal.

Abstract: A method and apparatus are disclosed for predistorting an input signal to a non-linear amplifier. An appropriate precorrection is determined for the input signal over a series of iterative stages according to an amplifier model. The amplifier model includes a limiting function that clips the input signal to reduce error due to amplifier saturation. The determined precorrection is then applied to the input signal.

Abstract: A method and apparatus are disclosed for predistorting an input signal to a non-linear amplifier. An appropriate precorrection is determined for the input signal over a series of iterative stages according to an amplifier model. The amplifier model includes a limiting function that clips the input signal to reduce error due to amplifier saturation. The determined precorrection is then applied to the input signal.