摘要:
A communication system and method is provided that modifies a signal (16) for transmission at a transmitter (12) to reduce peaks associated with the signal. The signal can be modified employing signal shaping, signal clipping, signal decomposition or other techniques to remove peaks associated with the signal. The communication system can also correct (28) the modified signal at a receiver (14) to reconstruct the originally wanted signal.
摘要:
Frequency synthesis is implemented by providing a delta-sigma modulated signal associated with a selected frequency, which frequency can vary based on a selection input. The delta-sigma modulated signal is converted from the digital to analog domain. The delta-sigma modulated signal can be provided directly from memory based on the selection input or, alternatively, it can be provided by a signal generator and processed by a delta-sigma modulator to provide the delta-sigma modulated signal. The selected frequency can be varied at a high rate of speed.
摘要:
A supply voltage and/or bias of a switching amplifier is modified based on at least one characteristic of the input signal relative to a threshold level. A binary waveform converter converts the input signal into a binary waveform for inputting into the switching amplifier. The switching amplifier amplifies the input signal, while the supply voltage and/or bias is modified in response to changes of the at least one characteristic of the input signal.
摘要:
An amplification system and method is provided that employs a digital cross-cancellation technique which provides a separate digital signal to be input to a separate DAC to generate a cancellation signal. The cancellation signal is added to the output of the amplifier to produce a final signal with substantially reduced distortion and/or out-of-band emissions. The cancellation signal can be pre-computed or derived by generating an inverted version of the wanted signal, and combining it with a portion of the output signal to determine the error or unwanted portion of the output signal. This error signal is then combined with a delayed version of the output signal.
摘要:
A conversion system converts an input signal from a digital signal to an analog signal over an extended dynamic range. The system includes a DAC system and a mode selector. The mode selector selects a mode of operation for the digital-to-analog converter system from a plurality of modes. The mode selector selects a mode according to a characteristic of the input signal. Each of the modes is associated with an instantaneous dynamic range and quantization noise level of the DAC system. The ensemble of modes provides an improvement in total or effective dynamic range compared to any single DAC component within the DAC system.
摘要:
Signal conversion of an input signal can be achieved by processing portions of the signal through plural parallel paths, which collectively approximate a desired infinite impulse response (IIR) filter, either alone or implemented with other signal processing functions. In one aspect, each of the paths can perform filtering, noise-shaping and/or quantization on a respective portion of the input signal to provide a corresponding representation of the respective portion of the input signal, for example, a coarser representation at a higher data rate. The corresponding representations from the parallel paths can be aggregated and further processed in a desired manner, such as conversion to an analog signal.
摘要:
An amplification system and method is provided that employs a digital cross-cancellation technique which provides a separate digital signal to be input to a separate DAC to generate a cancellation signal. The cancellation signal is added to the output of the amplifier to produce a final signal with substantially reduced distortion and/or out-of-band emissions. The cancellation signal can be pre-computed or derived by generating an inverted version of the wanted signal, and combining it with a portion of the output signal to determine the error or unwanted portion of the output signal. This error signal is then combined with a delayed version of the output signal.