function [U, S, V] = svd_decompose_channel(Mt, Mr, h_f, N);% [U S V] = svd_decompose_channel(Mt, Mr, h_f, N);%假設所有信道特性已知，那么傳輸是通過平行奇異值模型。這個函數就是將信道分解成幾個這樣的模型。% Function decomposes the channel at each subcarrier into its SVD components%%   Mt - # Tx antennas%   Mr - # Rx antennas%   h_f - MIMO impulse response - Mr rows, Mt*L columns, where L is the number of%         channel taps  L為信道有效時間%   N - # subcarriers子載波數U = [];S = [];V = [];for i = 1:N    [Utmp Stmp Vtmp] = svd(h_f(:,(i-1)*Mt+1:i*Mt));    U=[U Utmp];    V=[V Vtmp];    S=[S Stmp];endS = sum(S,1);