SOURCEFORGE » RALF » 2015 Simplified communications schemes of Voyager I probe

h1. BPSK link BER simulation

For a beginner of LABVIEW, The first step of simulation is building a BPSK communication chain with Gauss White Noise channel and without coding. 

!Communication_chain_without_coding.jpg!

Communication chain of BPSK without coding

Like the figure above, we first generate the pseudorandom series bits “0” or “1”, then use BPSK modulation, we make “0” with 0 radian phase, and “1” with pi radian phase. Put signal through the Gauss White Noise channel, of course the noise comes out through the Eb/N0 calibration module, the next step is BPSK demodulation, use it to recovery the information bits, then the last step if calculate the BER. According the different Eb/N0, we get the different BER, the we draw the BER curve as a function of Eb/N0, 

The following is the program block with G-language:

!Labview_blocks_without_coding1.jpg!

Figure of the communication chain blocks without coding 1

!Labview_blocks_without_coding2.jpg!

Figure of the communication chain blocks without coding 2

!Labview_blocks_without_coding3.jpg!

Figure of the communication chain blocks without coding 3

The interface of Labview is shown as following:

!Communication_chain_interface_without_coding.jpg!

Communication Chain interface without coding of BPSK

With this program we just need to set the number of block, and each block has 12 bits information. Of course if we want to get the value of BER is less than 1exp-6, we must set the number of block is much than 1exp8, so we get the value as following:

The results of BPSK simulation without coding

!BPSK_simulation_without_coding_results.jpg!

!BER_without_coding.jpg!

BER curve of BPSK simulation without coding

From the table and the BER curve above we can see that the simulation result almost the same with theory curve.