Abstract: This disclosure relates to a communication system including a modulator and a demodulator. The modulator produces a modulated signal including a carrier and data signals representing data bits. The data signals include at least two in-phase modulating pulses which have different shapes and which are interfering in time and frequency; the data signals further include at least two quadrature modulating pulses which have different shapes and which are interfering in time and frequency. The modulator includes a filter for producing each shape of pulse, and combining circuits for combining the pulses with each other and with a carrier. The demodulator (or receiver) receives the combined signal and separates the pulses from the carrier. The demodulator further includes filters for separating the pulses, and a circuit for processing the pulses to reproduce the data bits. The processing circuit preferably includes one or more maximum likelihood sequence estimation equalizers.

Abstract: A burst classifier is useful in a digital communication system transmitting a signal burst of a plurality of different burst types. The burst classifier includes a plurality of filters associated with the plurality of different burst types, respectively. Each filter generates correlation data based on the signal burst and a respective plurality of reference signals offset by a plurality of time offsets. The respective pluralities of reference signals are indicative of a corresponding burst type of the plurality of different burst types. A comparator then analyzes quantities based on the correlation data from each filter to determine the burst type of the signal burst.

Abstract: Apparatus comprising a decal disposed on an interior surface of a window and a light source for projecting light onto the to display an image outside of the vehicle. The decal comprises a protective layer having a hologram layer disposed thereon that is designed to transmit a holographic image in a predetermined viewing direction. An opaque and clear mask layer into which an icon is incorporated may be secured to the hologram layer to provide a two-dimensional image. The hologram layer is illuminated by sunlight, skylight, or a light source and projects an image to a viewer at a predefined direction. During the day, the icon is viewable because light transmits through the clear portions of the mask layer is clear, and is blocked by opaque portions of the mask layer that define the icon. At night, the decal is illuminated by light from a light source 18, or an exterior or ambient light source to produce an image viewable by the observer.

Abstract: A method and device for canceling frequency offsets in received modulated signals. The frequency offset cancellation device includes a downconverter module, a channel unit and a control module. The downconverter module shifts received signals to a lower frequency. The channel unit searches the shifted received signals and demodulates them, and the control module adjusts the downconverter in accordance with frequency offset information generated by the channel unit, thereby continuously cancelling out any frequency offsets that may have occurred during frequency shifting.