Therefore the output of the lowpass filter will just

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Unformatted text preview: discard the rest. Therefore, the output of the lowpass filter will just be a scaled version of the message signal. = 1 2 ΄ DSB-SC Page: 2 of 3 Effect of Noise on DSBSC In presence of noise, the input to the demodulator becomes: = + = = = = cos cos = = − cos 1 2 + cos sın − sin = The demodulator multiplies the input signal with a locally generated cos passes it through a low pass filter. = = 1 2 and cos = − = cos = sin cos − cos sin cos + cos 2 − sin 2 = = = = 1 2 = = = Note that, = 1 2 1 =2 = = 1 =4 1 4 1 4 1 4 1 2 = =2 The improvement in SNR results from the fact that the coherent detector rejects the Quadrature noise component in the input noise, thereby halving the mean-square noise power. DSB-SC Page: 3 of 3...
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This note was uploaded on 09/26/2012 for the course ETE ETE 321 taught by Professor Aqu during the Spring '12 term at North South University.

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