ELECTRONIC NOSE SYSTEMS Odorant molecules Chemical Information CIM Coated Sensor Raw electrical signal Sensor processor Processed electrical signal Signal processor Denoised Electrical signal
Hazard o Boolean algebra does not account for propagation delays through signal paths of actually circuits. o The delay can cause glitches to occur. A glitch is an unwanted signal, usually short pulse caused by the transient behavior of signal path that have different delays A hazard exists any time the potential for glitches is present
2.1 Discrete-Time Signals: Time-Domain Representation Signals represented as sequences of numbers, called samples Sample value of a typical signal or sequence denoted as x[n] with n being an integer in the range-oo≤n≤∞ x[n] defined only for integer values of n and undefined for noninteger values of n Discrete-time signal represented by {x[n]}
Introduction Basic signal properties(dc, rms, dBm. and power) Fourier transform and spectra Linear systems and linear distortion Bandlimited signal and sampling Discrete Fourier transform · Bandwidth of signal
Introduction Basic signal properties(dc, rms, dBm, and power) Fourier transform and spectra Linear systems and linear distortion Bandlimited signal and sampling Discrete Fourier transform Bandwidth of signal
Fouriers derivation of the ct fourier transform x(t)-an aperiodic signal view it as the limit of a periodic signal as t→∞ For a periodic signal the harmonic components are spaced Oo=2π/ T apart. AsT→∞,Obo→>0, and harmonic components are space
Noise is additional\unwanted \signal that interferes with the transmitted signal Generated by electronic devices The noise is a random process Each\sample \ of n(tis a random variable Typically, the noise process is modeled as\Additive White Gaussian noise”(AWGN) White: Flat frequency spectrur Gaussian noise distribution
