SCMA码本设计

yanzhxx

论文中“SCMA Codebook Design”中星座图旋转是对母星座图旋转还是对对形成母星座图的QPSK星座图旋转啊？

mengmeng202

你好，首先感谢提问。SCMA中的星座图旋转目的是防止用户在非正交扩频叠加的时候，造成解码的不唯一性。因此星座图旋转你可以理解为，先确定某一用户的星座，而其他用户基于此，然后通过旋转不同角度而得到。

Alam88

hi
Can you please help me how to design scma codebooks from mother constellation? I am implementing the *scma codebook design* paper. I have implemented untill the two projections of mother constellation(two 4x4 matrices). Now how can I get the codebooks (4x4).  The binary mapping matrix is 4x2 so i need a 2x4 matrix from the mother constellation..Please help me . how should I do this ? how to use the layer specific operator like phase rotation to get the codebook...  
Thanks and Regards
Mehmoodd.alam@gmail.com