Please, help me correct my "answers". Thank you.The communication channel (ideally) "lets through" frequencies from 450 Hz to 3250 Hz and has a signal / noise (S/N) ratio of 42 dB.

(a)How manysignal elements per second(bauds) is it possible to transfer over this channel?

(b)What is themax. bit rateover this channel?

(c)How do results from(a)and(b)influencemodem's properties?

(a)$\displaystyle \text{baud rate} \leq 2*\text{width}_\text{frequency}$? Reasoning: you only get 1 crest and 1 trough, hence this theoretical limit? So, if my reasoning is sound, thebaud rate$\displaystyle B\leq 2\omega = 2(3250\text{ Hz}-450\text{ Hz})=5600\text{ Bd}$

(b)Depends on number of states each baud (signal) can have. E.g. if a signal can be in 4 states, then each baud "carries" 2 bits, and themax. bit rate= 2 *baud rate.

As we're given the S/N ratio, we can use the equation for the channel capacity: $\displaystyle C=\omega * \underbrace{\log_2(1+\frac{S}{N})}_\textrm{the definition of dB?}\stackrel{?}{=} (3250\text{ Hz}-450\text{ Hz})*42\text{ dB}$

(c)We divide themax. bit ratefrom(b)by thebaud ratefrom(a)and get the number of bits/baud? That's all?

PS: I see that, instead of repairing the [tex] tag, you've just added the [TEX].