CDMA Modulation of String-to-Binary Bitstream (Simulink)

Simulink file converts an ASCII String to binary code. It uses Spread-Spectrum Code Division Multiplexing and Binary Phase-Shift Keying.

this Simulink file converts an ASCII String to binary code. It uses Spread-Spectrum Code Division Multiplexing and Binary Phase-Shift Keying (BPSK). the system takes a string, converts to ASCII, performs parallel-to-serial bit conversion, BPSK modulates the signals, spreads the spectrum with a unique psuedonoise (PN) code, adds the signals together in a common channel, despreads the spectrum with the same PN code, BPSK demodulates the signals, and performs serial-to-parallel conversion back into ASCII strings.

SEE THE REPORT INCLUDED IN THE ZIP FILE FOR ALL DETAILS.

this simulation was created for a Communications Systems course taken at California State Polytechnic University, Pomona under Dr. Zekeriya Aliyazicioglu.

the two main intentions were to 1: create a Simulink file capable of converting an ASCII-encoded string into a serially transmitted bitstream, and to 2: be able to view all stages of modulation and demodulation in the time and frequency domain, which is not always possible with Simulink's built-in modulation blocks.

you'll find most of the scopes under String A's subsystems. you can change the amount of noise with the AWGN. DISCLAIMER that only two active strings are currently possible while still maintaining accurate outputs. introducing the third string results in inaccurate outputs, likely due to increased noise