SYSTEM AND METHOD OF AN IN-BAND MODEM FOR DATA COMMUNICATIONS OVER DIGITAL WIRELESS COMMUNICATION NETWORKS

摘要

A SYSTEM IS PROVIDED FOR TRANSMITTING INFORMATION THROUGH A SPEECH CODEC (INBAND) SUCH AS FOUND IN A WIRELESS COMMUNICATION NETWORK. A MODULATOR (235) TRANSFORMS THE DATA INTO A SPECTRALLY NOISE-LIKE SIGNAL BASED ON THE MAPPING OF A SHAPED PULSE TO PREDETERMINED POSITIONS WITHIN A MODULATION FRAME, AND THE SIGNAL IS EFFICIENTLY ENCODED BY A SPEECH CODEC. A SYNCHRONIZATION SEQUENCE PROVIDES MODULATION FRAME TIMING AT THE RECEIVER (495) AND IS DETECTED BASED ON ANALYSIS OF A CORRELATION PEAK PATTERN. A REQUEST/RESPONSE PROTOCOL PROVIDES RELIABLE TRANSFER OF DATA USING MESSAGE REDUNDANCY, RETRANSMISSION, AND/OR ROBUST MODULATION MODES DEPENDENT ON THE COMMUNICATION CHANNEL CONDITIONS.