The purpose of this project is to encode a voice signal to be transmitted from a source to a receiver using digital technology. By reversing the frequencies in a voice pattern, the original voice signal can be scrambled. This reversal of frequencies is accomplished by mixing the voice signal with a cosine wave having a frequency equal to the sum of the highest and lowest frequencies of the voice signal. The output of the mixer is then sent to a low pass filter where the encoded message is extracted. The encoded voice is then passed along to a receiver where it undergoes the exact same process to decode the information, thus recovering the original voice signal. We achieved this encoding by performing the aforementioned steps on a digital signal processing chip (Texas Instrument's TMS320C26). Digital signal processing chips are becoming more popular in all forms of electronics today. Technology like this will be useful specifically to help prevent outside parties from overhearing cellular and cordless phone transmissions. 
 

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