Digital repeater having bandpass filtering, adaptive pre-equalization and suppression of natural oscillation

摘要

A signal repeating system includes at least one input antenna that receives input signals, at least one output antenna that radiates output signals, and a signal path between the input and output antennas. The signal path includes circuitry for conditioning the input signals with down conversion circuitry that converts input signals to lower frequency signals and analog-to-digital conversion circuitry that converts the input signals to digital signals. A suppression circuit suppresses feedback and interference in the repeated output signals with a digital signal processor configured for receiving samples of the input signals, samples of the output signals, and samples of an interference reference signal and an adaptive filter under the control of the digital signal processor for generating echo cancellation signals and interference cancellation signals.

主权项

1. A signal repeating system, comprising:
at least one input antenna that receives input signals, at least one output antenna that radiates output signals, and a signal path between the input and output antennas; the signal path including: down conversion and analog-to-digital conversion circuitry that converts the received input signals to lower frequency signals and that converts the received input signals to digital input signals; a suppression circuit for processing the digital input signals to produce digital output signals and for suppressing feedback and interference in the digital output signals, the suppression circuit including: a digital signal processor configured to receive the digital input signals, the digital output signals, and a digital interference reference signal; an adaptive filter coupled with the digital signal processor, the adaptive filter configured, under the control of the digital signal processor, for generating cancellation signals; the digital signal processor configured for computing a correlation between the digital input signals and the digital output signals and creating control signals for the adaptive filter to generate echo cancellation signals; the digital signal processor further configured to compute a correlation between the digital interference reference signal and the digital output signals and creating control signals for the adaptive filter to generate interference cancellation signals; combining circuitry for destructively adding the echo cancellation signals and the interference cancellation signals to the digital input signals for reducing echo and interference in the digital output signals of the signal repeating system; digital-to-analog conversion circuitry that converts the digital output signals to analog output signals and up conversion circuitry that converts the analog output signals to higher frequency signals.