function y1 = spheredecodeinf(rev,C,H, codebook)
[m,n]=size(H);      %m為Nr，n為Nt
T = zeros(1,n);   

[Q,R] = qr(H);    %QR分解
R = R(1:n, :);    %R= R（1：Nt，：）
ro = Q'*rev;  %y'=Q1'y
for ii = 1:n  %R為上三角矩陣
    if R(ii,ii) == 0
        R(ii,ii) = 0.001;
    end
    for jj = ii+1:n
        R(ii,jj) = R(ii,jj)/R(ii,ii); %為后面的運算做鋪墊
    end
    ro(ii) = ro(ii)/R(ii,ii);%相當于ym/Rmm，ym-1/Rm-1...
    R(ii,ii) = R(ii,ii)^2;
end
d = C;    %初始半徑
T(n) = 0; %T相當于是dm，m-1，m-2...的值，每維的半徑
S = ro;   %相當于ym/Rmm
cn = length(codebook); %碼本長度，4qam的話，就為2
len = zeros(1,n);
Y = zeros(n, cn);
ind = zeros(1,n);
y1 = zeros(n,1);
yt = [];
while 1
    k = n;                          %表示從第n維開始計算可能取值
    while k >= 1
       U =sqrt(d/R(k,k))+S(k);%上限值
       ii=cn;
        while ii >= 1 && U < codebook(ii)-10^(-11)
            ii = ii - 1;
        end
       L =-sqrt(d/R(k,k))+S(k);%下限值
       jj=1;
        while jj <= cn && L > codebook(jj)+10^(-11)
            jj = jj + 1;
        end
       len(k) = ii-jj+1;    %第K維的可能值的個數
       Y(k,:) = zeros(1, cn);
       yt = [];
        for kk = 1:len(k)
            yt = [yt codebook(jj+kk-1)];
        end
        [yt1, idex] = sort(abs(yt - S(k)));%按行升序排序
        yt = yt(idex);                     %yt存儲信號的可能取值    
        for kk = 1:len(k)
            Y(k,kk) = yt(kk);%從偏差最小的點開始存儲，按序，存儲信號的可能取值在Y里
        end
        ind(k)=0;%作為標記
        d1 = d+1;
        while d1 > d - 10^(-11)
            ind(k) = ind(k) + 1;
            while ind(k) > len(k)
                if k == n
%                     if y1~=zeros(n,1)
                         return       %結束，返回y1    
%                     else
%                           C=2*C;
%                           y1=spheredecode(rev, C, H, codebook);
%                           return  
%                     end   
                end
                k = k+1;   %表示在第k維中沒有找到值，則返回到k+1維中
                ind(k) = ind(k) + 1; %在第k+1維中從下一個點開始搜
            end
            if k > 1
              %  T(k-1) = T(k) - R(k,k)*(S(k)-Y(k,ind(k)))^2;%求dm-1的值，Y(k,ind(k))相當于第k維的取值   采用第二范數
               T(k-1)=max(T(k),R(k,k)*(S(k)-Y(k,ind(k)))^2);                                    % 采用無窮范數
                tmp = 0;
                for ii = k:n
                    tmp = tmp + R(k-1, ii)*Y(ii,ind(ii)) ;
                end
                S(k-1) = ro(k-1) - tmp;              %
                k = k - 1;                           %從第k維降到k-1維
                break;                               %跳出while循環              
            end
          %  d1 = T(n) - T(1) + R(1,1)*(S(1) - Y(1, ind(1)))^2;%k=1時的d1值
         d1 = max(T(1), R(1,1)*(S(1) - Y(1, ind(1)))^2); %k=1時的值    無窮范數
        end %while d1 > d
        if d1 < d-10^(-11)
            for ii=1:n
                y1(ii) = Y(ii, ind(ii));
            end
          d = d1;
        T(n)=0;
        break;
      end
    end %while k>=1
end %while 1 k=n