xample:8bit的ASC1l码“b的位式01100010 11000 1 0 0.50 0.25 0 Time 123456789101112131415 信号波形 谐波号 )sin(2ngdr)co2drd a,= an [cos(πn/4)-cos(3πn/4)+cos(6πn/4)-cos(7πn/4)] 元n 1 [sin(3元n/4)-sin(πn/4)+sin(7πn/4)-sin(6πn/4)] 元n c=3/4 The root mean square(rms)amplitudes is (an2+bn2)1/2 rms振幅的平方与对应频率的传输能量成正比信号波形 谐波号 Example: 8 bit的ASCII码“b”的位式 01100010 The root mean square (rms) amplitudes is (an 2+bn 2) 1/2 rms振幅的平方与对应频率的传输能量成正比 0 2 ( )sin(2 ) T n a g t nft dt T =   0 2 ( )cos(2 ) T n b g t nft dt T =   0 2 ( ) T c g t dt T = 