Abstract: A system and method for data communication over a cellular communications network that allows the transmission of digital data over a voice channel using a vocoder that monitors parameters of a Levinson Durbin recursion and then uses full rate CELP if the monitored prediction error falls to below a predetermined threshold within a pre-selected number of iterations of the recursion. The system and method encode digital data to be transmitted using a continuous signal modulation technique at a selected bit rate and one or more frequencies that are selected such that the resulting modulated carrier signal is processed by the vocoder using full rate CELP as a result of the monitored prediction error.

Abstract: A system and method for data communication over a cellular communications network that allows the transmission of digital data over a voice channel using a vocoder that operates in different modes depending upon characteristics of the inputted signal it receives. To prepare the digital data for transmission, one or more carrier signals are encoded with the digital data using one of a number of modulation schemes that utilize differential phase shift keying to give the modulated carrier signal certain periodicity and energy characteristics that allow it to be transmitted by the vocoder at full rate. The modulation schemes include DPSK using either a single or multiple frequency carriers, combined FSK-DPSK modulation, combined ASK-DPSK, as well as PSK with a phase tracker in the demodulator. These modulation schemes permit data communication via a CDMA, GSM, or other type of voice traffic channel at a low bit error rate.

Abstract: A system and method for asynchronous data communication over a cellular communications network that allows the transmission of different types of data frames over a voice channel using a vocoder. The data frames include a synchronization signal and data segment, with the synchronization signal being selected in accordance with an attribute of the data segment so that, upon receipt of the data frame, the synchronization signal can be used by the demodulating modem to determine not only where the data segment begins, but also to identify what type of data segment is in the received data frame. The synchronization signals used have low cross-correlation and an auto-correlation function that approximates a unit impulse function to provide reliable transmission through the vocoder.

Abstract: A system and method for asynchronous data communication over a cellular communications network that allows the transmission of different types of data frames over a voice channel using a vocoder. The data frames include a synchronization signal and data segment, with the synchronization signal being selected in accordance with an attribute of the data segment so that, upon receipt of the data frame, the synchronization signal can be used by the demodulating modem to determine not only where the data segment begins, but also to identify what type of data segment is in the received data frame. The synchronization signals used have low cross-correlation and an auto-correlation function that approximates a unit impulse function to provide reliable transmission through the vocoder.

Abstract: A system and method for data communication over a cellular communications network that allows the transmission of digital data over a voice channel using a vocoder that monitors parameters of a Levinson Durbin recursion and then uses full rate CELP if the monitored prediction error falls to below a predetermined threshold within a pre-selected number of iterations of the recursion. The system and method encode digital data to be transmitted using a continuous signal modulation technique at a selected bit rate and one or more frequencies that are selected such that the resulting modulated carrier signal is processed by the vocoder using full rate CELP as a result of the monitored prediction error.

Abstract: A system and method for data communication over a cellular communications network that allows the transmission of digital data over a voice channel using a vocoder that operates in different modes depending upon characteristics of the inputted signal it receives. To prepare the digital data for transmission, one or more carrier signals are encoded with the digital data using one of a number of modulation schemes that utilize differential phase shift keying to give the modulated carrier signal certain periodicity and energy characteristics that allow it to be transmitted by the vocoder at full rate. The modulation schemes include DPSK using either a single or multiple frequency carriers, combined FSK-DPSK modulation, combined ASK-DPSK, as well as PSK with a phase tracker in the demodulator. These modulation schemes permit data communication via a CDMA, GSM, or other type of voice traffic channel at a low bit error rate.

Abstract: A system and method for data communication over a cellular communications network that allows the transmission of digital data over a voice channel of the communications network. Digital data is encoded into DBPSK data using differential binary phase shift keying encoding. The DBPSK data is then sent across the cellular network using a vocoder having a linear predictive or other speech compression codec. At the receiving end, the DBPSK data is demodulated back into the original digital data. This approach permits data communication via a CDMA, GSM, or other type of voice traffic channel at a low bit error rate.