Collaborative Covert Communication Design Based on Lattice Reduction Aided Multiple User Detection Method

Algorithm 2

Algorithm LR-MUD.

1: Estimation of signals Y is calculated by matched filters.

Signal power, relative delay, and carrier phase difference of signals are estimated.

2: A correlation matrix between signals is calculated.

3: Process H with lattice reduction algorithm (LLL or Seysen).

Conversion matrix and optimized matrix is obtained.

4: The ZF or MMSE method is implemented

5: The modified quantization in improved lattice space is taken:

is the power normalization parameter, and is the roundness of real value.

6: Final detection result   is calculated.