A communication channel is subjected to additive burst noise that occurs at random times with a ten-percent duty cycle. This means that the burst noise occupies ten percent of any time interval that is long compared to the duration of individual bursts. During the burst, the signal-to-noise ratio is 0 dB and the additive noise probability density function is unknown; otherwise, the signal-to-noise ratio is 30 dB and the noise is additive gaussian noise.
a. Specify a combination of a multilevel signaling scheme and a Reed- Solomon code that will give a good performance on this channel. What is the data rate?
b. An alternative signaling scheme is proposed that allegedly mitigates the effects of the burst noise. The proposal is to transform signal intervals of duration T into another orthogonal coordinate system. (A Fourier transform is one such transformation.) The alleged justification is that the burst noise is "spread out" in the new coordinate system. Is this proposal sound? What data rate may be expected by using this method?
c. To mitigate the effects of defects in an optical storage medium, a proposal is made to use the Fourier transform property of holography to "spread" the effect of the defects over all stored bits. Is this a sound technique?