Abstract: A radio communication apparatus operable over a wide range of frequencies including a signal processing device is provided. The device performs an analog to digital conversion at a predetermined sample rate independent of a selected frequency band within the wide range of frequencies to generate a digital signal, and digitally processes the digital signal to output a data signal at baseband associated with the selected frequency band.

Abstract: Transmitter observation receivers and methods are described that can predistortion-compensate transmitters capable of operating in multiple communication bands and frequency ranges. Such observation receivers and method involve generating at least one compensation signal such that a signal to be transmitted that is within a bandwidth that simultaneously encompasses multiple frequency ranges is compensated.

Abstract: A method and apparatus for compression of complex data signals within a telecommunications base station. The method includes representing a sample of a complex value discrete time signal using 2(L?N)?S mantissa bits and 2N+S exponent bits to realize peak output signal to noise ratios over a wider dynamic range compared to a conventional L-bit uniform quantization format. The increases in dynamic range and peak output SNR is achieved without increasing the average number of data bits per sample and with relatively simple computational effort.

Abstract: This specification discloses a level de-multiplexed DSM based transmitter and a method for providing the same. Broadly embodiments of the present specification enable wireless transmitters that are based on multi-level de-multiplexed DSM. A three-level de-multiplexed DSM based transmitter is disclosed as an example. More generally, the use of m-level de-multiplexed DSM is also taught, the specification thereby being enabling for broader applications to a person skilled in the art. At least one of the efficiency and linearity of transmitters can be enhanced as required for specific applications by a person of skill in the art in view of this specification and the teachings of its disclosed embodiments.

Abstract: A radio communication apparatus operable over a wide range of frequencies including a signal processing device is provided. The device performs an analog to digital conversion at a predetermined sample rate independent of a selected frequency band within the wide range of frequencies to generate a digital signal, and digitally processes the digital signal to output a data signal at baseband associated with the selected frequency band.

Abstract: Disclosed is a signal splitting apparatus useable in a power amplifier having two or more power amplifiers. The apparatus includes a direct gain component; and a derived gain component connected to the direct gain component. The derived gain component derives the derived gain by imposing a constraint which is valid over the entire dynamic range of the input signal, e.g. the sum of the power of the direct split signal and the derived split signal are constrained to be substantially equal to the power of the input signal. The use of combining additional direct gain and derived gain components, as well as a delay element, are disclosed so as to enable n-component splitting that for adaptation to different applications by the use of suitable coefficients.

Abstract: A method and an apparatus for augmenting timing synchronization in a base station using backhaul network frequency synchronization are provided. When in a first mode an external time epoch reference synchronized with system time is used to synchronize the base station to system time. When in a second mode a network frequency reference recovered from a backhaul network link is used to maintain the timing synchronization.

Abstract: A method and system adaptively reduce a peak-to-average power ratio in a communication system. Energy is clipped from at least one peak of a modulated signal. The modulated signal includes a plurality of sub-carriers. At least one data sub-carrier is adaptively selected for peak-to-average power ratio reduction use based on known scheduling information. The clipped energy is distributed among at least one data sub-carrier.

Abstract: Embodiments of a digital up-conversion system for a concurrent multi-band signal and methods of operation thereof are disclosed. In one embodiment, a digital up-conversion system includes multiple digital up-converter chains, each for a different frequency band of the concurrent multi-band signal, and a digital combiner that combines up-converted signals output by the digital up-converter chains to provide a combined digital signal. The combined digital signal is processed by one or more additional processing components including a digital-to-analog converter (DAC) to provide the concurrent multi-band signal.

Abstract: A receiver and method is provided for sigma-delta converting an RF signal to a digital signal and downconverting to a digital baseband signal. The RF signal is split into N phases, as can be accomplished using a sample and hold circuit, and each phase is digitized, as can be accomplished using an analog-to-digital (A/D) sigma-delta converter. Polyphase decimation techniques and demodulation are applied to the phased signals to generate a demodulated digital signal. The demodulated digital signal is further downconverted to the appropriate baseband signal.

Abstract: A receiver and method is provided for sigma-delta converting an RF signal to a digital signal and downconverting to a digital baseband signal. The RF signal is split into N phases, as can be accomplished using a sample and hold circuit, and each phase is digitized, as can be accomplished using an analog-to-digital (A/D) sigma-delta converter. Polyphase decimation techniques and demodulation are applied to the phased signals to generate a demodulated digital signal. The demodulated digital signal is further downconverted to the appropriate baseband signal.

Abstract: Systems and methods for characterizing an undersampled receiver are disclosed. In one embodiment, one or more probe signals are provided to an input of an undersampled receiver. Each of the one or more probe signals has selective frequency components that ensure that aliases in a corresponding output signal of the undersampled receiver are unique. The undersampled receiver is then characterized based on the output signal(s) of the undersampled receiver. The selective frequency components of the one or more probe signals enable un-aliasing of the one or more output signals of the undersampled receiver and, as such, the undersampled receiver can be characterized.

Abstract: Disclosed is a signal splitting apparatus useable in a power amplifier having two or more power amplifiers. The apparatus includes a direct gain component; and a derived gain component connected to the direct gain component. The derived gain component derives the derived gain by imposing a constraint which is valid over the entire dynamic range of the input signal, e.g. the sum of the power of the direct split signal and the derived split signal are constrained to be substantially equal to the power of the input signal. The use of combining additional direct gain and derived gain components, as well as a delay element, are disclosed so as to enable n-component splitting that for adaptation to different applications by the use of suitable coefficients.

Abstract: A communication system comprising signal processing circuitry and up-conversion circuitry. The signal processing circuitry is configured to: i) generate a first signal of a first modulation type and a second signal of a second modulation type; ii) combine the first and second signals to form a combined input signal; iii) generate peak reduction distortion based on the combined input signal; iv) select a portion of the peak reduction distortion that corresponds to a first frequency band; and v) apply the selected portion of the peak reduction distortion in the first frequency band of the combined input signal to provide a combined output signal. The up-conversion circuitry up-converts the combined output signal to an RF signal for transmission.

Abstract: The present disclosure relates to digital up-conversion for a multi-band Multi-Order Power Amplifier (MOPA) that enables precise and accurate control of gain, phase, and delay of multi-band split signals input to the multi-band MOPA. In general, a multi-band MOPA is configured to amplify a multi-band signal that is split across a number, N, of inputs of the multi-band MOPA as a number, N, of multi-band split signals, where N is an order of the multi-band MOPA and is greater than or equal to 2. A digital upconversion system for the multi-band MOPA is configured to independently control a gain, phase, and delay for each of a number, M, of frequency bands of the multi-band signal for each of at least N?1, and preferably all, of the multi-band split signals.

Abstract: Transmitter observation receivers and methods are described that can predistortion-compensate transmitters capable of operating in multiple communication bands and frequency ranges. Such observation receivers and method involve generating at least one compensation signal such that a signal to be transmitted that is within a bandwidth that simultaneously encompasses multiple frequency ranges is compensated.

Abstract: A method for operating an integrated transceiver, comprising coupling an operating transmitter and an operating receiver within the integrated wideband receiver, inputting a signal into the operating transmitter, performing a first conversion of the signal, wherein the signal is converted into a second signal, transmitting the second signal into the operating receiver, performing a second conversion of the signal, wherein the signal is converted into a third signal, transmitting the third signal into the operating transmitter, and adjusting the operating transmitter.

Abstract: A method and system adaptively reduce a peak-to-average power ratio in a communication system. Energy is clipped from at least one peak of a modulated signal. The modulated signal includes a plurality of sub-carriers. At least one data sub-carrier is adaptively selected for peak-to-average power ratio reduction use based on known scheduling information. The clipped energy is distributed among at least one data sub-carrier.

Abstract: A communication system comprising signal processing circuitry and up-conversion circuitry. The signal processing circuitry is configured to: i) generate a first signal of a first modulation type and a second signal of a second modulation type; ii) combine the first and second signals to form a combined input signal; iii) generate peak reduction distortion based on the combined input signal; iv) select a portion of the peak reduction distortion that corresponds to a first frequency band; and v) apply the selected portion of the peak reduction distortion in the first frequency band of the combined input signal to provide a combined output signal. The up-conversion circuitry up-converts the combined output signal to an RF signal for transmission.

Abstract: Digital predistorter circuits with selectable basis function configurations are described. In some embodiments, an input scaling block is introduced prior to a basis function generator structure. The input scaling factor is based on the input signal's average power. In other embodiments, configurable connection coefficients are used to construct the orthogonal basis functions. Multiple sets of tap weights for the predistorter are maintained, each set corresponding to a given basis function configuration. In an example method for pre-distorting an input signal to compensate for distortion introduced by an electronic device, a statistic characterizing the input signal is calculated, and one of a pre-determined set of basis function configurations is selected, based on the statistic.