Abstract: A system of energy detection for detecting a valid signal in a modem to enable power savings in receiver and transmitter circuits. The method of energy detection includes the steps of: (a) processing a prescribed number of signal samples (e.g. typically between 512 and 2048); (b) determining an average energy level for the prescribed number of signal samples; (c) determining a gain of an amplifier based on the processed signal samples; (d) comparing the average energy level with a prescribed energy level threshold; and (e) comparing the gain of the amplifier with a prescribed amplifier gain threshold. If the average energy level is greater than the prescribed energy level threshold and if the gain of the amplifier is less than the prescribed amplifier gain threshold then a valid signal is declared and the transmitter of the modem is activated.

Abstract: An automatic gain control method and apparatus for modem receivers. The automatic gain control circuit includes a programmable loop gain for scaling a digital signal Y to a first prescribed level during a first mode of operation and to a second prescribed level during a second mode of operation; and filters and converters for converting the scaled signal Y into an analog gain control signal for input to the analog AGC. The gain control circuit and method of operation provides control over the parameters of the programmable loop gain such that during start-up initialization the signal Y is scaled to the first prescribed value and during steady state operation the signal Y is scaled to the second prescribed value. This is accomplished by changing the gain parameter of the programmable loop gain.

Abstract: A method is disclosed for integrating a message such as an icon at a specified location within a graphical image. The method includes the steps of first retrieving transformation parameters associated with the specified location of the graphical image. The message or icon is then transformed in accordance with the retrieved transformation parameters and subsequently superimposed on top of the graphical image. As a result, an integrated image is created which is conveyed to the electronic display. The method has particular industrial applicability to streamed content such as conveyed on television and over the Internet. Also disclosed is a method for identifying transformation parameters useful in specifying a locality within a graphical image wherein a frame of a graphical image is displayed as a background image and a another, preselected message is displayed as a foreground image. The method permits translation and scaling of the foreground image while the background image remains unaffected.