Ask an algebraic operation problem about thp precoding module in MIMO system.

For example, assuming QPSK modulation, the constellation area of QPSK is 4 square areas. The purpose of mod is to remap those points (caused by lower triangular array coding) whose constellation falls outside the four designated areas back to these four areas.

I don't know what you mean by mod_num here; If the understanding is correct, the boundary length value of remapping should be determined, for example, 0.5+0.5j is the center point, and all points in the square area with the side length of 1 are determined as the first quadrant? Then four quadrants and four small squares add up to a big square. This big square is a square with the origin as the center and the side length of 2, so the boundary value is equal to 2. If it exceeds this boundary, such as r (1) =1.5+1.5j, it should be remapped to -0.5-0.5j If r(3)=0.5+2.5j, it should be remapped to 0.5+0.5j (first

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Taking r(3)=0.5+2.5j as an example, both methods are correct. You can get a result of 0.5+0.5j, but,

Take r (1) =1.5+1.5j as an example.

The first method is mod (1.5+ 1, 2)- 1 = 0.5- 1 =-0.5, which is correct.

The second method is mod (1.5,2) =1.5, invariant, error.

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It can be seen that this planar two-dimensional mapping can not be completed simply by taking the module directly. First+1, then mod2, and then subtract 1, in order to consider the negative value around the origin.

If your constellation point symbol set is centered on (1, 1) instead of the origin, then direct mod2 can meet the requirements.

If you answer well, give me a little more reward. I am very poor recently.

You can write to me, and welcome to exchange questions in this regard. ? Lucy leaf? Where is it? gmail.com