If the multipath delays, typically a few microseconds for outdoor
communications, are significant with respect to the symbol period, then intersymbol interference will occur. Note: this effect of multipath
propagation is not an additional form of distortion to frequency selective fading but
rather the same effect viewed in the time domain.
|
![]() |
![]() |
It should be noted that propagation delay itself is not a major problem, but rather the spread of delays over the different propagation paths. Shown here is a typical plot of the amplitude and delay profile for a cellular telephone signal as it propagates within a city centre. The spread of time delays is about 15 ms for the significant components. |