lstrz/dsss-illustrated

Direct Sequence Spread Spectrum illustrated

dsss-illustrated's Issues

Basic definations in the spread sprectrum

What if i want to just do a simulation on lower frequency let's say 25KHz I had tried with the code already it looks like the coarse_acquisition_code_signal is calculated incorrectly . Here is the case test run :

This is coarse_acquisition_code_frequency :  2500.0
Base frequency:  25000
Carrier frequency:  175000
CA code frequency:  2500.0
Message frequency:  500
Reference frequency:  32000
Reference multiplier:  5
Mixer frequency:  160000
Intermediate frequency:  15000
Filter bandwidth:  4000
Sampling frequency:  68000.0
Carrier done.
CA code done.
Message done.

message_signal.shape = (48972,)
carrier_signal.shape = (48999,)
(coarse_acquisition_code_signal.shape = (0,)
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-24-2baee26d4572> in <module>
    320 print(coarse_acquisition_code_signal)
    321 
--> 322 output_signal = message_signal * carrier_signal * coarse_acquisition_code_signal
    323 print("Output done.")
    324 

ValueError: operands could not be broadcast together with shapes (48972,) (48999,) 

I may be wrong somewhere. Can you please explain how can i calculate relative reference frequency and sampling rate ? Do we need intermediate frequency at all ? Can i just by pass those ?

Thanks.

Is there a way to Generate CDMA signal using this ?

Its more than question than issue. Can we use this to generate CDMA signal ? If yes than which one is better OFDM or CDMA ?

Divide by zero error, time_start and time_end are integers, need to be floating point

New to all of this but had to fix one line to get this project to run in Python 2.7
time_start and time_end need to be float, as is they are integers. If you change time_start = 0 to time_start = 0.0 and time_end = 1.0 / message... this has fixed the problem and allows code to work.