摘要:
A wireless receiver comprises a band-pass filter module that includes an input for receiving a first pilot signal, an output that generates a first signal based on the first pilot signal, and a control input for adjusting a center frequency of the band-pass filter module. A control module determines the energy of the first signal, generates a control signal based on the energy, and communicates the control signal to the control input of the band-pass filter module.
摘要:
Systems, apparatus and methods are provided for detecting the mode of a received OFDM signal. A received signal may be correlated with one or more time-delayed version of itself resulting in a set of correlation signals. Each correlation signal may be analyzed for one or more characteristics that can be used to determine the symbol length of the received signal. In order to minimize the number of correlations performed, one or more correlations can be used with varying symbol lengths and a fixed guard interval length. The correlation signals can be processed by filters, and the characteristics of the filtered correlation signals can be analyzed to determine the guard interval length of the received signal. In addition to detecting symbol length, the present invention can be used to detect receiver impairment and perform any appropriate compensations.
摘要:
An adaptive analog echo/near-end crosstalk (NEXT) cancellation system includes a bit slicer that receives a first analog receive signal and that generates a first error control signal. A digital signal processor (DSP) receives a digital receive signal and a digital transmit signal and generates second and third error control signals. A first summing module generates a fourth error control signal by summing the second and third error control signals. A selector outputs the first error control signal during a first mode and the fourth error control signal during a second mode. An echo/NEXT cancellation module communicates with the selector and generates an estimated echo/NEXT signal based on the first error control signal and an analog transmit signal during the first mode and based on the fourth error control signal and the analog transmit signal during the second mode.
摘要:
A network device including a physical layer (PHY) device and an autonegotiation module. The PHY device is configured to interface with N cable pairs, where N is greater than 1. The PHY device includes a cable test module configured to diagnose a short circuit in one of the N cable pairs. The autonegotiation module is configured to i) selectively perform autonegotiation to establish a link with a link partner at one of a first link speed and a second link speed that is lower than the first link speed, and ii) select between the first link speed and the second link speed in response to the cable test module diagnosing the short circuit.
摘要:
Apparatus and methods relating to channel equalization include a method including: generating a first output signal in a frequency domain based on a communications signal of a channel; determining a first channel response based on the first output signal and one or more pilot signals of the communications signal; generating a first equalized signal based on the first output signal and the first determined channel response; generating a first decision signal based on the first equalized signal; generating an output signal in a time domain based on the first decision signal; determining a second channel response based on the time domain output signal; generating a second output signal in the frequency domain based on the second channel response; generating a second equalized signal based on the first and second output signals and the time domain output signal; and generating a second decision signal based on the second equalized 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 duty cycle estimator comprises an error generator that compares an output of a switching regulator to a reference to generate an output error, wherein the switching regulator operates in accordance with a switching period. An accumulator determines an accumulated error of the output error over a time period of at least N times the switching period of the switching regulator, where N is an integer. An adjustment determiner adjusts a duty cycle for the switching regulator based on the accumulated error of the output error over the time period.
摘要:
A controller comprises a duty cycle estimator to determine a nominal duty cycle. An adjustment determiner determines an adjustment value to combine with the nominal duty cycle to generate an adjusted duty cycle. A pulse width adjuster varies a pulse width signal based on the adjusted duty cycle. Transfer of energy between an input and a regulated output is based on the pulse width signal.
摘要:
Circuits, methods, apparatus, and systems for recovering a clock from a spread spectrum signal having a periodic modulation profile. The circuits generally include an error detector circuit configured to compare the spread spectrum signal and a recovered clock signal, and to produce a first error signal corresponding to the periodic modulation profile and a second error signal corresponding to phase differences other than the spread spectrum modulation, a record and playback unit configured to record a value to a frequency memory, said value based on the first error signal and produce a third error signal corresponding to a predicted periodic modulation based at least in part on the recorded value, and a signal generator configured to produce the recovered clock signal in response to the second and third error signals.
摘要:
Systems and techniques relating to image cancellation in received communications signals are described. In one aspect, a received communications signal can include a desired signal and an image signal. A leakage tracing signal can be generated, and the image signal can be removed from the communications signal using the leakage tracing signal mixed with the communications signal. Implementations can include generating a first channel signal and a second channel signal, generating a first filter using the first channel signal and the leakage tracing signal, and generating a second filter using the second channel signal and the leakage tracing signal. Removing the image signal from the communications signal can include filtering the first channel signal using the second filter to obtain a first filtered signal, filtering the second channel signal using the first filter to obtain a second filtered signal, and subtracting the second filtered signal from the first filtered signal.