Angle Modulation

  • R. F. W. Coates
Part of the Electrical and Electronic Engineering book series


In the introduction to chapter 3, we stated that modulation of a sinusoidal carrier was employed to effect a spectral relocation of baseband information. We saw that linear envelope-modulation, defined by the relation
$$v\left(t \right) = \left\{ {k{v_m}\left(t \right) + c} \right\}\cos \left({2\pi {f_c}t + {\phi _c}} \right)$$
also provided a small improvement in noise immunity. When the carrier is immersed in gaussian noise, we find that the signal-to-noise ratio at the detector output is 3 dB higher than the carrier-to-noise ratio at its input. This improvement is only obtained at the expense of additional transmission bandwidth, since the spectrum of the modulated carrier occupies twice the bandwidth of the spectrum of the baseband modulating-signal.


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Copyright information

© R. F. W. Coates 1982

Authors and Affiliations

  • R. F. W. Coates
    • 1
  1. 1.University of WalesUK

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