A STUDY OF THE FEASIBILITY OF MULTIPLEXING TELETYPE DATA INTO NONSPEECH TIME OF VOCODED SPEECH TRANSMISSION

摘要

The purpose of this report is to discuss the findings of one phase of Air Force Study Contract AF19(628)-345 wherein Texas Instruments Incorporated was requested by the Data Sciences Laboratory at Air Force Cambridge Research Laboratories to investigate and prepare a separate report on the feasibility of multiplexing teletype data into the silent frames of vocoder speech.nSpecifically the investigation was to determine (1) the number of teletype transmission channels that might be accommodated (multiplexed) simultaneous with vocoder speech communication system used for speech transmission, (2) the buffer storage requirements to realize the potential teletype trans¬mission rate available due to the silent frames, (3) and the general imple¬mentation problem that would be encountered in adding the teletype multiplexing feature into the polymodal vocoder designed and built for AFCRL by Texas Instruments (Contract AF19(628)-302).nResults of the study were very significant, it was found that for normal telephone conversations it would be possible to multiplex in 39, 75-word-per-minute teleprompters into a full duplex vocoder speech communication system. In addition, it would be possible to have these 39 teleprompters running 97 percent of the time while the system was in use for speech transmission. The amount of equipment necessary to implement the teletype multiplexing function was found to be quite small, hereby, adding very little to the anticipated size and weight of vocoder systems of the near future.