摘要:
Traditionally, pipelined continuous-time (CT) sigma-delta modulators (SDM) have been difficult to build due at least in part to the difficulties in calibrating the pipeline. Here, however, a pipelined CT SDM is provided that has an architecture that is conducing to being calibrated. Namely, the system includes a digital filter and other features that can be adjusted to account for input imbalance errors and well as quantization leakage noise.
摘要:
Traditionally, pipelined continuous-time (CT) sigma-delta modulators (SDM) have been difficult to build due at least in part to the difficulties in calibrating the pipeline. Here, however, a pipelined CT SDM is provided that has an architecture that is conducing to being calibrated. Namely, the system includes a digital filter and other features that can be adjusted to account for input imbalance errors and well as quantization leakage noise.
摘要:
Compressive sensing is an emerging field that attempts to prevent the losses associated with data compression and improve efficiency overall, and compressive sensing looks to perform the compression before or during capture, before energy is wasted. Here, several analog-to-digital converter (ADC) architectures are provided to perform compressive sensing. Each of these new architectures selects resolutions for each sample substantially at random and adjusts the sampling rate as a function of these selected resolutions.
摘要:
Traditionally, pipelined continuous-time (CT) sigma-delta modulators (SDM) have been difficult to build due at least in part to the difficulties in calibrating the pipeline. Here, however, a pipelined CT SDM is provided that has an architecture that is conducing to being calibrated. Namely, the system includes a digital filter and other features that can be adjusted to account for input imbalance errors and well as quantization leakage noise.
摘要:
Compressive sensing is an emerging field that attempts to prevent the losses associated with data compression and improve efficiency overall, and compressive sensing looks to perform the compression before or during capture, before energy is wasted. Here, several analog-to-digital converter (ADC) architectures are provided to perform compressive sensing. Each of these new architectures selects resolutions for each sample substantially at random and adjusts the sampling rate as a function of these selected resolutions.
摘要:
Traditionally, pipelined continuous-time (CT) sigma-delta modulators (SDM) have been difficult to build due at least in part to the difficulties in calibrating the pipeline. Here, however, a pipelined CT SDM is provided that has an architecture that is conducing to being calibrated. Namely, the system includes a digital filter and other features that can be adjusted to account for input imbalance errors and well as quantization leakage noise.
摘要:
An analog-to-digital converter (ADC) is provided. The ADC includes a plurality of pipelined ADCs and an adjustment circuit. Each pipelined ADC is adapted to receive an analog input signal, has an adjustable transfer function, and includes a compensator. The adjustment circuit is coupled to each pipelined ADC to be able to adjust the transfer function for each pipelined ADC so as to generally eliminate an estimation ambiguity. Additionally, the adjustment circuit estimates an inter-stage error that includes at least one of an inter-stage gain error and a DAC gain error and adjusts the compensator for each pipelined ADC to compensate for the inter-stage error.
摘要:
An analog-to-digital converter (ADC) is provided. The ADC includes a plurality of pipelined ADCs and an adjustment circuit. Each pipelined ADC is adapted to receive an analog input signal, has an adjustable transfer function, and includes a compensator. The adjustment circuit is coupled to each pipelined ADC to be able to adjust the transfer function for each pipelined ADC so as to generally eliminate an estimation ambiguity. Additionally, the adjustment circuit estimates an inter-stage error that includes at least one of an inter-stage gain error and a DAC gain error and adjusts the compensator for each pipelined ADC to compensate for the inter-stage error.
摘要:
The present invention provides an enhanced channel estimator for use with an orthogonal frequency division multiplex (OFDM) receiver employing scattered pilot channel estimates. In one embodiment, the enhanced channel estimator includes a time interpolation estimator configured to provide time-interpolation channel estimates having at least one image for a portion of carriers having the scattered pilot channel estimates. The enhanced channel estimator also includes a frequency interpolation estimator coupled to the time interpolation estimator and configured to provide frequency-interpolation channel estimates for each carrier based on image suppression through balanced-error filtering.
摘要:
A process of estimating an admittance of an RF component using a ladder network with alternating series and parallel components by making three VSWR measurements and computing three admittance circle solutions in the complex admittance plane. The admittances circles are transformed through reference planes of the ladder network to obtain three RF component admittance circles, then estimating the RF component admittance using three nearest intersections of the three RF component admittance circles. Reference planes are defined immediately upstream and immediately downstream of each component of the ladder network. The transforms are performed using lumped parameter models of the series and parallel components of the ladder network.