Abstract: A radio is disclosed. The radio system includes radio system nodes that are configured with a transceiver to transmit and receive information over more than one frequency. Each radio system node also includes a processor, the processor being any of a variety of processing elements, including but not limited to general purpose processors, coders, decoders, and the like. The processor is configured to gather a block of information and configured to format the block of information into a plurality of sub blocks. Each sub block of information includes message synchronization information. The sub blocks are dispersed in time and over the more than one frequency and substantially simultaneous transmission and reception of multiple transmissions in the same frequency band is enabled.

Abstract: A radio is disclosed. The radio system includes radio system nodes that are configured with a transceiver to transmit and receive information over more than one frequency. Each radio system node also includes a processor, the processor being any of a variety of processing elements, including but not limited to general purpose processors, coders, decoders, and the like. The processor is configured to gather a block of information and configured to format the block of information into a plurality of sub blocks. Each sub block of information includes message synchronization information. The sub blocks are dispersed in time and over the more than one frequency and substantially simultaneous transmission and reception of multiple transmissions in the same frequency band is enabled.

Abstract: An air traffic control system in which an airborne GPS receiver on a trans-oceanic flight is provided pseudo range correction data and satellite integrity information from a group of terrestrial HF transmitters, transmitting on a common set of frequencies and using a time division multiplexing scheme.

Abstract: A method and apparatus are provided for modulating an intermediate frequency of a radio frequency transmitter with a digital sample stream. The method includes the steps of interpolating the digital sample stream by an over sampling factor and modulating the interpolated digital sample stream to a single bit sample stream, while spreading and shaping quantization noise created by the modulation outside a bandwidth of the intermediate frequency. The method further includes the steps of converting the single bit sample stream to an analog signal and bandpass filtering the analog signal around the intermediate frequency.