Methods for building, transmitting, and receiving frame structures in power line communications (PLC) are described. Various techniques described herein provide a preamble design using one or more symbols. One or more preamble symbols may be interspersed within a header portion of a PLC frame to facilitate estimation of a frame boundary and/or sampling frequency offset, for example, in the presence of impulsive noise.

Methods for building, transmitting, and receiving frame structures in power line communications (PLC) are described. Various techniques described herein provide a preamble design using one or more symbols. One or more preamble symbols may be interspersed within a header portion of a PLC frame to facilitate estimation of a frame boundary and/or sampling frequency offset, for example, in the presence of impulsive noise.

Signal correction circuitry is described that improves the integrity of data transmitted over a serial data interface without interrupting the communication between the connected devices. The signal correction circuitry includes edge correction circuitry that speeds up the rising and falling edges of the data signal(s). The signal correction circuitry also includes DC compensation circuitry that boosts the level(s) of the data signal(s).

Signal correction circuitry is described that improves the integrity of data transmitted over a serial data interface without interrupting the communication between the connected devices. The signal correction circuitry includes edge correction circuitry that speeds up the rising and falling edges of the data signal(s). The signal correction circuitry also includes DC compensation circuitry that boosts the level(s) of the data signal(s).

Aspects of the subject disclosure may include, a system that facilitates detecting first electromagnetic waves propagating along a transmission medium are experiencing a first propagation loss, inducing second electromagnetic waves along the transmission medium to mitigate the first propagation loss, detecting that the second electromagnetic waves are experiencing a second propagation loss and inducing third electromagnetic waves along the transmission medium to mitigate the second propagation loss. To reduce radiation losses when transitioning from the first electromagnetic waves to second electromagnetic waves and transitioning from the second electromagnetic waves to the third electromagnetic waves, the system can be further adapted to use differing criteria for each transition. Other embodiments are disclosed.

Aspects of the subject disclosure may include, a system that facilitates detecting first electromagnetic waves propagating along a transmission medium are experiencing a first propagation loss, inducing second electromagnetic waves along the transmission medium to mitigate the first propagation loss, detecting that the second electromagnetic waves are experiencing a second propagation loss and inducing third electromagnetic waves along the transmission medium to mitigate the second propagation loss. To reduce radiation losses when transitioning from the first electromagnetic waves to second electromagnetic waves and transitioning from the second electromagnetic waves to the third electromagnetic waves, the system can be further adapted to use differing criteria for each transition. Other embodiments are disclosed.

An air conditioning system includes an outdoor unit and an indoor unit connected to the outdoor unit through an air conditioning communication line. The outdoor unit includes: a control unit; a compressor; a fan; a compressor inverter; a fan inverter; a heat exchanger; and valves of various types. The control unit of the outdoor unit has a coupling capacitor and a noise-cutting transformer which are between a communication circuit and the air conditioning communication line.

In a communication apparatus, an analog circuit includes a circuit element to be connected to a first conductor, and processes a differential signal. A communication circuit receives, via a connection circuit, a differential signal processed by the analog circuit, and generates a signal for which the potential of a second conductor is used as a reference potential based on the received differential signal. An inductor is connected between the first conductor and the second conductor. The connection circuit includes a circuit element different from a capacitor. The analog circuit (21), the connection circuit, the communication circuit, the inductor, the first conductor, and the second conductor are housed in a conductive housing box.

The invention relates to a method of cancelling noise present in a data signal received on an electrical bifilar line (L), implemented by a sender-receiver device (M) comprising a first transformer (TD), termed the differential mode circuit, comprising a primary side (TDp) and a secondary side (TDs), the primary side being connected by two wires to the bifilar line, a second transformer (TC), termed the common mode circuit, comprising a primary side (TCp) and a secondary side (TCs), the primary side being connected by a wire (c) to the primary side (TDp) of the differential mode circuit, and to an earth by another wire, the method comprising the following steps during an adjustment phase: obtaining a first value of voltage on the bifilar line, termed the differential mode voltage; obtaining a second value of voltage corresponding to a voltage at the level of the two wires of the secondary side of the common mode circuit, termed the image voltage of the common mode, resulting from said differential mode voltage; calculating the ratio between the second value and the first value, termed the noise conversion ratio; and the method comprising the following steps during a cancellation phase, subsequent to the adjustment phase; receiving the data signal originating from the bifilar line; simultaneously with the receiving step, obtaining a third value corresponding to the voltage at the level of the two wires of the secondary side of the common mode circuit; cancelling the noise in the data signal, by subtracting an estimation of the noise, the estimation being calculated by dividing the third value by said conversion ratio.

The invention relates to a method of cancelling noise present in a data signal received on an electrical bifilar line (L), implemented by a sender-receiver device (M) comprising a first transformer (TD), termed the differential mode circuit, comprising a primary side (TDp) and a secondary side (TDs), the primary side being connected by two wires to the bifilar line, a second transformer (TC), termed the common mode circuit, comprising a primary side (TCp) and a secondary side (TCs), the primary side being connected by a wire (c) to the primary side (TDp) of the differential mode circuit, and to an earth by another wire, the method comprising the following steps during an adjustment phase: obtaining a first value of voltage on the bifilar line, termed the differential mode voltage; obtaining a second value of voltage corresponding to a voltage at the level of the two wires of the secondary side of the common mode circuit, termed the image voltage of the common mode, resulting from said differential mode voltage; calculating the ratio between the second value and the first value, termed the noise conversion ratio; and the method comprising the following steps during a cancellation phase, subsequent to the adjustment phase; receiving the data signal originating from the bifilar line; simultaneously with the receiving step, obtaining a third value corresponding to the voltage at the level of the two wires of the secondary side of the common mode circuit; cancelling the noise in the data signal, by subtracting an estimation of the noise, the estimation being calculated by dividing the third value by said conversion ratio.