sentences:  The first term, HkWks"k", represents the desired signal, and the second term, formula_2, represents interference received by user "k".The network channel is defined as H = [H1T,…, H"K"T]T, and the corresponding set of signals received by all users is expressed by
  
  y = HWs + n,
  
  where H = [H1T,…, HK"T]T, y = [y1T,…, yK"T]T, W = [W1T,…, WK"T]T, s = [s1T,…, sK"T]T, and n = [n1T,…, n"K"T]T.
  
  The precoding matrix W is designed based on channel information in order to improve performance of the Cooperative-MIMO system.Alternatively, receiver-side processing, referred to as spatial demultiplexing, separates the transmitted symbols.