초록 ▼

A communications system capable of simultaneously transmitting voice and data information. The spectral energy of the data signal is smeared by spreading it in a spectrum with energy packed in the lower frequency range under the conventional voice signal frequency in a manner which complements the s

A communications system capable of simultaneously transmitting voice and data information. The spectral energy of the data signal is smeared by spreading it in a spectrum with energy packed in the lower frequency range under the conventional voice signal frequency in a manner which complements the standard C-message weighting curve. The use of the spread spectrum technique also eliminates thumping at the data rate since the harmonics that produce thumping are also spread throughout the bandwidth.

대표청구항 ▼

A method for communicating data information over a communications medium at frequencies less than voice transmission frequencies comprising: generating at least one digital data signal; generating at least one spreading frequency; combining the data signal and spreading frequency to create a spreadi

A method for communicating data information over a communications medium at frequencies less than voice transmission frequencies comprising: generating at least one digital data signal; generating at least one spreading frequency; combining the data signal and spreading frequency to create a spreading code for transmission of the data which causes the data to be transmitted at three or more fundamental frequencies; and transmitting the fundamental frequencies as a coherent frequency modulated signal having a constantly varying fundamental frequency less than the voice frequency bandwidth.