Matlab实现量化过程（均匀量化）Matlab实现量化过程（均匀量化）
对信号进⾏2到8bit量化，并对两种量化⽅式的量化噪声作对⽐clc;
clear
n=1:2000;
y=sin(2*pi*n/100)+0.5*cos(2*pi*n/200)+2*sin(2*pi*n/300);
for bits=2:8
figure(bits-1);
v=0:2^bits;
m=-2.6+(2.6+2.6)/2^bits*v; %量化
v1=1:2^bits;
p_round=m(v1)+(m(v1+1)-m(v1))/2; %中间值
%画原函数图
subplot(3,1,1);
plot(n,y);
grid on;
title('y(n)');
axis([0,2000,-3.5,3.5]);
%画round()函数量化图
y_round=y;
for i=1:2000
for j=1:2^bits
if(y(i)>=m(j)&&y(i)
y_round(i)=p_round(j);
end;
end;
end;
subplot(3,1,2);
plot(n,y_round);
title('round(n)');
grid on;
axis([0,2000,-3.5,3.5]);
%画floor()函数量化图
y_floor=y;
for i=1:2000
for j=1:2^bits
if(y(i)>=m(j)&&y(i)
y_floor(i)=m(j);
end;
end;
end;
subplot(3,1,3);
plot(n,y_floor);
grid on;
title('floor(n)');
axis([0,2000,-3.5,3.5]);
%计算SNR
Y_power=sum(y.^2)/2000;
round_power=sum((y-y_round).^2)/2000;
SNR_round(1)=0;
SNR_round(bits)=Y_power/round_power;
floor_power=sum((y-y_floor).^2)/2000;
SNR_floor(1)=0; SNR_floor(bits)=Y_power/floor_power; end; %结束2-8⽐特循环
SNR_round_db=10*log10(SNR_round)
SNR_floor_db=10*log10(SNR_floor)
%画SNR图
figure(8);
axis_x=1:8;
plot(axis_x,SNR_round_db);
title('量化信噪⽐');
hold on;
plot(axis_x,SNR_floor_db,'r');
grid on;
axis([2,8,0,50]);
xlabel('bit');
ylabel('SNR/dB');
legend('round','floor');
运⾏结果：
SNR_round_db =
-Inf 12.5760 18.4032 24.3451 30.7085 36.7237 42.6317 48.4947
SNR_floor_db =
-Inf 6.5254 12.5704 18.5765 24.6524 30.6839 36.6813 42.6456
上⼀条线为round函数产⽣的量化信噪⽐，下⼀条线为floor函数产⽣的量化信噪⽐。
>round函数怎么使用matlab