Abstract: A coupling circuit for a power line communications system for coupling information signals from a transmitter unit to a power line and for coupling information signals from the power line to a receiver unit. The coupling circuit includes: (a) a ferrite core coupler for isolating the transmitter unit or the receiver unit from a power line and for coupling information signals from the transmitter unit to the power line and from the power line to the receiver unit, (b) a bandpass filter for selectively passing information signals from the transmitter unit to thew power line and from the power line to the receiver unit, and (c) an impedance matching pad for matching the impedance of the transmitter unit to the impedance at an outlet connected to the power line and to which the transmitter unit is connected and the receiver unit to the impedance at an outlet connected to the power line and to which the receiver unit is connected.

Abstract: In response to a received carrier wave modulated in accordance with a digital signal, a digital radio receiver recovers in digital form a modulating signal that is at times subject to undesirable amounts of multipath distortion. This recovered modulating signal is applied as respective input signals to first and second finite-impulse-response (FIR) filters, each of an N-tap type, the taps of which are adaptively weighted. The first FIR filter responds to the modulating signal to supply an output signal in which multipath distortion is suppressed. The second FIR filter responds to the modulating signal to generate corrections for the tap weights of the first FIR filter, which corrections are generated more rapidly than can be done with a microprocessor of the type commonly known as a "digital signal processor" or "DSP". A digital comparator compares samples of the first FIR filter response to corresponding samples of an ideal response, thereby to generate updated tap weights for the second FIR filter.