摘要:
Methods, software, receivers and systems for communicating information over a cyclostationary channel. The method generally includes interleaving sections of a control sequence with bits of the information. The software and receivers are generally configured to implement one or more aspects of the methods disclosed herein, and the systems generally include those that embody the inventive receivers disclosed herein. The present invention is particularly useful in powerline channels, where certain parameters (such as noise) have time-dependent or periodic variations in value. By distributing the control sequence, the incidence of carrier recovery is reduced, the likelihood of successful packet or frame transmissions is increased, and data may be more reliably communicated.
摘要:
A transceiver including an equalizer, and a control circuit. The equalizer includes i) a unity tap comprising a coefficient input configured to receive a coefficient equal to 1, ii) a first plurality of taps including a first plurality of coefficient inputs—each configured to receive a respective one of first coefficients, wherein the first plurality of taps generate a first output signal based on an input, iii) a second plurality of taps including a second plurality of coefficient inputs—each configured to receive a respective one of second coefficients, wherein the second plurality of taps are configured to filter the first output signal to generate a second output signal. The control circuit is configured to limit a sum of the first coefficients and the second coefficients to a first predetermined range based on the coefficient of the unity tap.
摘要:
A digital signal processor includes an up-sampling module that samples an input signal and generates up-sampling points. A natural sampling module includes a reference signal generation module that generates a reference signal. A crossing point detection module receives the up-sampling points and the reference signal and uses interpolation to detect intersection points of the input signal and the reference signal. The crossing point detection module determines values of the input signal at first and second evaluation times. The crossing point detection module estimates a current intersection point of the input signal and the reference signal as an intersection of the reference signal and a line that extends between first and second points on the input signal that correspond with the first and second evaluation times. A frequency of the reference signal is variable and a current switching period of the reference signal is not equal to a previous switching period.
摘要:
Systems and techniques relating to image cancellation in received communications signals are described. A described technique includes receiving a communications signal including a desired signal and an image signal; generating a leakage tracing signal at a frequency band of the image signal, the leakage tracing signal including a noise signal, a frequency of the leakage tracing signal being within the frequency band of the image signal; and removing the image signal from a signal that is based on the communications signal and the leakage tracing signal to resolve the desired signal, where the removing is based on an addition of the leakage tracing signal to the communications signal. Removing the image signal can include using one or more weights to control one or more filters to resolve the desired signal. The one or more weights can be determined based on the noise signal.
摘要:
A regulated power supply includes an inverter comprising an upper switch and a lower switch that are connected in series. A control module selectively controls the upper switch and the lower switch in one of a pulse width modulation (PWM) mode and a discrete control mode (DCM), receives a feedback signal from an output of the regulated power supply, and switches between the PWM mode and the DCM based on the feedback signal.
摘要:
A noise shaping module includes a first addition module that receives an N-bit digital input signal, where N is an integer greater than one. A first filter module generates a first filtered output signal based on an output signal of the first addition module. A truncation module generates an M-bit truncated output signal based on the first filtered output signal, where M is an integer less than N. A second filter module generates a second filtered output signal based on the M-bit truncated output signal. The second filtered output signal is an input to the first addition module.
摘要:
Systems and techniques relating to channel equalization in received communications signals are described. In one aspect, a communications signal of a channel is obtained and channel effects are removed from the communications signal by generating one or more time-varying channel response estimates.
摘要:
Methods and systems for filtering an input signal include receiving a first demodulated signal produced by multiplying a first generated signal with a received input signal, receiving a second demodulated signal produced by multiplying a second generated signal with the received input signal, and producing first and second filtered output signals by applying a transfer function to the first and second demodulated signals, wherein the transfer function comprises a first filtering coefficient, wherein the first filtering coefficient defines a matrix comprising one or more non-symmetrical terms. An application of the transfer function can compensate for one or more of an amplitude mismatch between the first and second generated signals, a phase mismatch between the first and second generated signals, and one or more frequency handling characteristics of channels used to produce the first and second demodulated signals.
摘要:
A method of sensing current comprises providing a current sensor having a gain resolution; setting the gain resolution of the current sensor to an initial resolution; sensing current flowing through the current sensor; evaluating an amplitude of the current; and changing the gain resolution of the current sensor based on the evaluating.
摘要:
An RF receiver image rejection scheme. The RF is received and mixed in two quadrature channels allowing separation of the undesired image portion within the RF signal from the desired portion. The two channels can be summed to allow the image portions to cancel out and form a signal which is predominantly based on the desired portion. Another sum of the two channels can also be made to provide a signal which is primarily based on the image portion. Since there are some components of the image portion even in the compensated desired signal, that signal indicative of the image portion is used to compensate for that undesired portion.