SYSTEM AND METHOD OF IN-BAND MODEM FOR DATA TRANSMISSION OVER DIGITAL WIRELESS COMMUNICATION NETWORKS Russian patent published in 2012 - IPC H04J3/06 H04L7/04 G10L19/00 

FIELD: physics, communications.

SUBSTANCE: invention relates to data transmission over a voice channel, particularly transmission of non-speech information through a speech codec (within the bandwidth) over a communication network. The method of obtaining non-speech data embedded in a vocoder packet involves receiving and decoding the vocoder packet; filtering the decoded vocoder packet until a synchronisation signal is detected; calculating a timing offset based on the synchronisation signal; and extracting the non-speech data embedded in the decoded vocoder packet based on the timing offset. Filtering involves steps of correlating the decoded vocoder packet with a pseudorandom noise sequence to generate a plurality of correlation peaks and comparing the plurality of correlation peaks with an expected pattern. Correlation includes a step for correlating one of the non-overlapping or overlapping composite preamble sequence of the decoded vocoder packet with the pseudorandom noise sequence. The expected pattern is based on a combination of negative and positive correlation peaks. The comparison employs a certain number from the plurality of correlation peaks, which is matched with the expected pattern, and determining whether said number exceeds a predetermined value.

EFFECT: high efficiency of in-band data transmission through a speech codec in a wireless communication system.

28 cl, 41 dwg, 6 tbl