CA code for GPS PRN-1

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vimal kumar chawda
vimal kumar chawda 2019-11-24
回答： Markandeya Janaswamy 2023-3-1
Hello
1-Does anyone know how to generate the CA code for GPS
PRN_6_CA=dec2base(1455,2);
PRN_16_CA=dec2base(1776,2);
PRN_26_CA=dec2base(1761,2);
x=1;
G_1=1+x^3+x^10;
j=1;
k=10;
for i=1:1023
for j=1:10;
x(j)=
ca_1(i,:)=[x1 x2 x3 x4 x5 x6 x7 x8 x9 x10];
y=x3+x5;
end
if y==2
x1=0;
else x1=1
end
if G_1==(G_1/2)
y=x3+x5;
if y==2
x2=0;
else x2=1
end
i=i+1;
k=k+1;
end
end
I want to know how to shift the first value to right side if we have 10 value in the one row. So new data is entering at 1st place is sum of the 3rd and 10th place then convert it into binary form which is new value at 1st position. Hence we have to do till 1023 times.
One can see the video to know more what we have to do in the exercise.
https://www.youtube.com/watch?v=F0RRQ6eJVJQ&t=2s

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采纳的回答

Kaashyap Pappu
Kaashyap Pappu 2019-11-27
编辑：Kaashyap Pappu 2020-1-14
You can use the comm.PNSequence object to generate the gold code for both generators. For the second generator, you will have to set the mask property to the appropriate phase delay polynomial, and number of bits out as 1023.
chips = 1023;
genG1 = [10 7 0]; % 1 + x^3 + x^10
initVector =[1 1 1 1 1 1 1 1 1 1];
generator = comm.PNSequence('Polynomial',genG1,...
'InitialConditions',initVector,'SamplesPerFrame',chips);
Generate similarly for generator G2 using the phase delay polynomial as the mask, add both sequences using Modulo-2 addition using xor and you will have your sequence.
Hope this helps!
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Kaashyap Pappu
Kaashyap Pappu 2019-12-16
  1. The mask would be the phase selection polynomial for each satellite vehicle. You can use a switch case setup for each satellite separately.
  2. Generator polynomial is given the in the technical specification. Specify powers of X as a vector.
  3. Initial states is a binary vector indication the starting state of the Linear Feedback Shift Register setup.
  4. Current state is the current output values for each the registers.
  5. ... is basically to inform the MATLAB compiler that the command is continued on the next line. This is used for readability.
The Blue data indicate properties of the specific object. The black highlighted variables are the user defined property values.
ScubaNinjaDog
ScubaNinjaDog 2022-9-6
But the ouput of the second generator is not directly used like with the first generator.

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更多回答（2 个）

Rajkumar Mishra
Rajkumar Mishra 2020-9-17
Hello,
in the solution above is not the second term be '3' inplace of '7' as mentioned in this line
genG1 = [10 7 0]; % 1 + x^3 + x^10
Markandeya Janaswamy
From R2021b, Satellite Communications Toolbox supports generating C/A-codes. Use the function gnssCACode. See https://mathworks.com/help/satcom/ref/gnsscacode.html

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