Abstract: A method of transmitting information is provided. The method is performed at a system for information transfer. The method includes obtaining a first symbol, in a predefined set of symbols, for transmission; determining a first frequency band, in a first set of frequency bands associated with the predefined set of symbols, that is associated with the first symbol; and transmitting a first signal pulse having a first frequency in the first frequency band. The method includes, after transmitting the first signal pulse, transmitting a control signal associating a second set of frequency bands with the predefined set of symbols. The second set of frequency bands is distinct from the first set of frequency bands.

Abstract: A method of receiving information is provided. The method, performed at a system for information transfer, includes receiving a first signal pulse and determining a first frequency band associated with the first signal pulse. The method includes, in accordance with a determination that the first frequency band is a respective frequency band in a first set of frequency bands, determining, from a predefined set of symbols associated with the first set of frequency bands, a first symbol associated with the first frequency band and represented by the first signal pulse. The first set of frequency bands includes a second frequency band that is a nearest frequency band in the first set of frequency bands to the first frequency band. The first frequency band has a first center frequency; the second frequency band has a second center frequency; and a difference between the first center frequency and the second center frequency exceeds a frequency difference threshold.

Abstract: A method of receiving information is provided. The method, performed at a system for information transfer, includes receiving a signal pulse and determining a frequency band and a pulse duration associated with the signal pulse. The method includes, in accordance with a determination that the frequency band is one of a set of frequency bands, determining, from a first set of symbols, a first symbol associated with the frequency band. The method also includes, in accordance with a determination that the pulse duration is one of a set of pulse durations, determining, from a distinct second set of symbols, a second symbol associated with the pulse duration. Each frequency band in the set of frequency bands is associated with a respective symbol in the first set of symbols, and each pulse duration in the set of pulse durations is associated with a respective symbol in the second set of symbols.

Abstract: A method of receiving information is provided. The method is performed at a system for information transfer. The method includes receiving a first signal pulse and determining a first frequency band and a first pulse duration associated with the first signal pulse. The method includes, in accordance with a determination that the first frequency band is one of a predefined set of frequency bands, and that the first pulse duration is one of a predefined set of pulse durations, determining, from a predefined set of symbols, a first symbol associated with the first frequency band and the first pulse duration. Each frequency band in the predefined set of frequency bands is associated with a respective set of two or more symbols, and each symbol of a respective set of two or more symbols is associated with a distinct respective pulse duration in the first predefined set of pulse durations.

Abstract: A method of receiving information is provided. The method is performed at a system for information transfer. The method includes receiving a first signal pulse and determining a first frequency band associated with the first signal pulse. The method includes, in accordance with a determination that the first frequency band is a respective frequency band in a predefined set of frequency bands, determining, from a predefined set of symbols, a first symbol associated with the first frequency band and represented by the first signal pulse and providing the first symbol. Each frequency band in the predefined set of frequency bands is associated with a distinct respective symbol in the predefined set of symbols, and frequency bands in the predefined set of frequency bands, in aggregate, are not contiguous.