56 lines
1.3 KiB
Matlab
56 lines
1.3 KiB
Matlab
clc
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clear
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%================================================
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%已知抽样值以△为单位
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%================================================
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x = 500
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pcmcode = pcmEnCode(x)
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amp = pcmDeCode(pcmcode)
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qerror = x-amp
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%================================================
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%已知抽样值为实际电压值，则需先转换为以△为单位
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%================================================
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M = 5
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d = M/2^11;
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x = 2.5
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x0 = round(x/d)
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pcmcode = pcmEnCode(x0);
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amp0=pcmDeCode(pcmcode);
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amp0 = amp0*d
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qerror=x-amp0
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function pcmcode = pcmEnCode(s)
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start_t=[0,2.^(4:11)];
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width_t=[1,1,2,4,8,16,32,64];
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pcm=0;
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if s>0
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pcm=pcm+bitshift(1,7);
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else
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s=abs(s);
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end
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for i = 0:7
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if s < start_t(i+2)
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pcm=pcm+bitshift(i,4);
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pcm=pcm+floor((s-start_t(i+1))/width_t(i+1));
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break
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end
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end
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pcmcode=dec2bin(pcm,8);
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end
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function amp = pcmDeCode(pcmcode)
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start_t=[0,2.^(4:11)];
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width_t=[1,1,2,4,8,16,32,64];
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code=bin2dec(pcmcode);
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ucode=bitand(code,0b01111111);
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k=bitshift(ucode,-4);
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m=bitand(ucode,0b00001111);
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amp=start_t(k+1)+double(m)*width_t(k+1)+width_t(k+1)/2;
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if code<=128
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amp=-amp;
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else
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amp=amp;
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end
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end
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