CORDIC算法的matlab实现
本帖最后由 大笨象 于 2011-6-7 12:26 编辑不知道有木有人研究这个，比较偏向于硬件描述。
今天先发一个sine cose函数的实现。
有兴趣的可以看一下，m文件见附件。
function v=f_cordic(beta,n)
if beta < -pi/2 || beta > pi/2
if beta < 0
v=f_cordic(beta + pi,n);
else
v=f_cordic(beta - pi,n);
end
v = -v;% flip the sign for second or third quadrant
return
end
% Initialization of tables of constants used by CORDIC
% need a table of arctangents of negative powers of two, in radians:
% angles = atan(2.^-(0:27));
angles = [ ...
0.78539816339745 0.46364760900081 0.24497866312686 0.12435499454676 ...
0.06241880999596 0.03123983343027 0.01562372862048 0.00781234106010 ...
0.00390623013197 0.00195312251648 0.00097656218956 0.00048828121119 ...
0.00024414062015 0.00012207031189 0.00006103515617 0.00003051757812 ...
0.00001525878906 0.00000762939453 0.00000381469727 0.00000190734863 ...
0.00000095367432 0.00000047683716 0.00000023841858 0.00000011920929 ...
0.00000005960464 0.00000002980232 0.00000001490116 0.00000000745058 ];
% and a table of products of reciprocal lengths of vectors :
Kvalues = [ ...
0.70710678118655 0.63245553203368 0.61357199107790 0.60883391251775 ...
0.60764825625617 0.60735177014130 0.60727764409353 0.60725911229889 ...
0.60725447933256 0.60725332108988 0.60725303152913 0.60725295913894 ...
0.60725294104140 0.60725293651701 0.60725293538591 0.60725293510314 ...
0.60725293503245 0.60725293501477 0.60725293501035 0.60725293500925 ...
0.60725293500897 0.60725293500890 0.60725293500889 0.60725293500888 ];
Kn = Kvalues(min(n, length(Kvalues)));
% Initialize loop variables:
v = ; % start with 2-vector cosine and sine of zero
poweroftwo = 1;
% Iterations
for j = 1:n;
if beta < 0
sigma = -1;
else
sigma = 1;
end
% update the angle from table, or eventually by just dividing by two
if j <= length(angles)
angle = angles(j);
else
angle = angle/2;
end
factor = sigma * poweroftwo;
R = ;
v = R * v; % 2-by-2 mtrix multiply
beta = beta - sigma * angle; % update the remaining angle
poweroftwo = poweroftwo / 2;
end
% Adjust length of output vector to be :
v = v * Kn;
return
使用20位寄存器，仿真波形如下：
我表示学习了 这是什么算法？第一次听说{:3_41:} 我表示很给力 zhangjichang 发表于 2011-6-8 22:31 static/image/common/back.gif
这是什么算法？第一次听说
这个，就是那个。感兴趣的话你还是自己搜搜吧。 赛才 发表于 2011-6-9 15:01 static/image/common/back.gif
我表示很给力
给力就好。呵呵 顶一下！{:soso_e100:} 费解。。。。。。。。。。。。。。。。 有什麽用？求解 {:3_41:}{:3_41:}{:3_41:}