Abstract: A method is provided for enhancing a legacy satellite digital radio audio service (SDARS) by overlaying a hierarchically modulated data stream on a base layer (legacy) data stream and improving the synchronization of the received signal in which an overlay layer frame is synchronized to a base layer frame. The base layer frame includes additional data that is used to synchronize the receivers to demodulate and decode the overlay layer and the base layer. The additional data is modulated using a technique that aids the receiver in synchronizing the received signal that is different from the overlay layer.

Abstract: A method is provided for enhancing a legacy satellite digital radio audio service (SDARS) by overlaying a hierarchically modulated data stream on a base layer (legacy) data stream to increase the amount of data transmitted in the SDARS system. Using improved (next generation) receiver designs, additional services can be provided to users while existing legacy receivers can continue to receive the services broadcast on the base layer modulated data stream in the legacy system.

Abstract: A method is provided for enhancing a legacy satellite digital radio audio service (SDARS) by overlaying a hierarchically modulated data stream on a base layer (legacy) data stream and improving the synchronization of the received signal in which an overlay layer frame is synchronized to a base layer frame. The base layer frame includes additional data that is used to synchronize the receivers to demodulate and decode the overlay layer and the base layer. The additional data is modulated using a technique that aids the receiver in synchronizing the received signal that is different from the overlay layer.

Abstract: An antenna (110), enclosed within a compact area of a radio (100), is not susceptible to electric fields generated from metallic shields (102, 104) located within the radio. The antenna consists of four sections of traces disposed onto a circuit board (108). The first section is a quarter-wave feed (202), which is coupled to a radio transceiver (118). The quarter-wave feed (202) converts a low impedance point (122) to a high impedance region (203). The second section of antenna (110) capacitively couples to the high impedance region (203). The third section is an isolator section (208) of half a wavelength for providing isolation from the shields (102, 104). The fourth section, quarter-wavelength radiator (214), is a trace electrically equivalent to a quarter of a wavelength having a high impedance and providing the radiating port of the antenna (110).